Introduction to Date Values
Introduction to Date Values
Dates Fundamentals
Introduction
A date is a measure of non-spatial units that have elapsed in a set period. To perform this measure, a certain point is set and called midnight. Because the light in daily life changes from one midnight unit to the next midnight unit, the sub-point when the light shows up, or starts, is called sunrise. The sub-point when the light diminishes or starts disappearing is called sunset.
The group of units between two midnight points is called a day. The days are counted from 1, 2, 3, and so on.
Practical Learning: Introducing Date Values
Date Value Creation
To represent the dates, computers, applications, and compilers are configured with specific techniques. In Microsoft Windows, to manage dates, the operating system in its Win32 library provides a structure named SYSTEMTIME. To manage dates, the .NET Framework provides a structure named DateTime. To create a date value, you can first declare a DateTime variable. To assist you with initializing the variable, the DateTime structure is equipped with various constructors.
The default constructor allows you to create a date or a time object without specifying its details. This would be done as follows:
using System;
namespace DateAndTime
{
public class Exercise
{
public static int Main()
{
DateTime tm = new DateTime();
return 0;
}
}
}
After declaring a DateTime variable and initializing it, it holds all necessary pieces of information about its date and its time values.
Primary Characteristics of a Date
The Day of a Date Value
A day is the period from one midnight to the next midnight (or just before midnight). To make it easy to identify a day, the days in US English are named Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday. To support the day, the DateTime structure is equipped with a read-only property named DayOfWeek. The value of this property is from en enumeration of the same name:
public DayOfWeek DayOfWeek { get; }
The members of the DayOfWeekenumeration are Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday. Use the DateTime.DayOfWeek property to get the name of a day of a date value. Here is an example:
using System;
namespace DateAndTime
{
public class Exercise
{
public static void Main()
{
DateTime infractionDate = new DateTime();
Console.WriteLine("Day: " + infractionDate.DayOfWeek);
Console.WriteLine("=============================");
return;
}
}
}
This would produce:
Day: Monday ============================= Press any key to continue . . .
A Week
A week is a group of seven consecutive days.
A Month
By essence, a month is a group of four consecutive weeks. To support the month, the DateTime structure is equipped with a read-only integer property named Month:
public int Month { get; }
The integer type represents the position of the month within the year if the date. The months are counted from 1 and up. To make it easy to identify a month, each month holds a name, long or short. In US English, the long names of months are January, February, March, April, May, June, July, August, September, October, November, and December. The short names of months in US English are Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, and Dec.
A Year
A year is a group of 12 consecutive months. To support the year value, the DateTime structure is equipped with a numeric property named Year:
public int Year { get; }
The Day of a Year
A year is a series of days, 360, 365, or 366, depending on some factors. The days are numbered as 1, 2, 3, and so on. To support the days of a year, the DateTime structure is equipped with a numeric property named Day:
public int Day { get; }
Date Creation
To create a date value, you should (must) provide the year, the month in that year, and the day in that month. To support this way of creating a date, A date is a technique of identifying a period using three numbers: the year, the month, and the day. To support this way of creating a date value, the DateTime structure is equipped with the following constructor:
public DateTime(int year, int month, int day);
The value of a year is a number between 1 and 9999. The value of the month must be between 1 and 12. The values of the day are as follows:
| Month | Days Between 1 and |
| Jan or January | 31 |
| Mar or March | 31 |
| Apr or April | 30 |
| May | 31 |
| Jun or June | 30 |
| Jul or July | 31 |
| Aug or August | 31 |
| Sep or September | 30 |
| Oct or October | 31 |
| Nov or November | 30 |
| Dec or December | 31 |
Depending on a factor named Leap Year, the month of Feb or February can have days between 1 and 28 or 1 and 29. When February has 28 days, the year has 365 days, otherwise it has 366 days. Here is an example of creating a date:
using System;
namespace DateAndTime
{
public class Exercise
{
public static int Main()
{
DateTime ind = new DateTime(1960, 1, 1);
return 0;
}
}
}
To display a date value, you can pass it to the Console.Write() or the Console.WriteLine() method. Here is an example:
using System;
namespace DateAndTime
{
public class Program
{
public static int Main()
{
DateTime ind = new DateTime(1960, 1, 1);
Console.WriteLine("Independence Day: {0}", ind);
return 0;
}
}
}
This would produce:
Independence Day: 1/1/1960 12:00:00 AM Press any key to continue . . .
We already saw how to get the day, the month, and the year of a date value. Once you have a date value, the name of the day of that date is represented by the DateTime.DayOfWeek property. Here is an example:
using System;
namespace DateAndTime
{
public class Membership
{
public static void Main()
{
DateTime independence = new DateTime(1962, 7, 5);
Console.Write("Independence Day: " + independence.DayOfWeek);
Console.WriteLine(" " + independence);
Console.WriteLine("=============================");
return;
}
}
}
This would produce:
Independence Day: Thursday 7/5/1962 12:00:00 AM ============================= Press any key to continue . . .
The Default Date Value
The default constructor of the DateTime structure initializes the date to January 1st, 0001 and the time at midnight. This is illustrated in the following program:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime tm = new DateTime();
Console.WriteLine("Default Date and Time: {0}", tm);
return 0;
}
}
}
This would produce:
Default Date and Time: 1/1/0001 12:00:00 AM Press any key to continue . . .
This also means that the lowest date and time values that a DateTime object can hold is January 1st, 0001 at 00:00:00. This value is represented by the MinValue constant member of the DateTime structure. The highest date and time that a DateTime object can hold in the structure is called MaxValue and it is set at December 31, 9999.
Requesting a Date Value
As done with the regular numbers, you can request a date value from the user. This is also done by requesting a string from the user. Here is an example:
using System;
namespace ValueRequests
{
class Exercise
{
static void Main()
{
string strDateHired;
strDateHired = Console.ReadLine();
}
}
}
After the user has entered the string, you can convert it to a DateTime value. Just like any value you request from the user, a date or time value that the user types must be valid, otherwise, the program would produce an error. Because dates and times follow some rules for their formats, you should strive to let the user know how you expect the value to be entered.
By default, if you request only a date from the user and the user enters a valid date, the compiler would add the midnight value to the date. If you request only the time from the user and the user enters a valid time, the compiler would add the current date to the value.
Practical Learning: Requesting a Date Value
using System;
namespace GeorgetownDryCleaningServices
{
class GeorgetownDryCleaningServices
{
public static int Main(string[] args)
{
// Price of items
const double PriceOneShirt = 1.25;
const double PriceAPairOfPants = 2.15;
const double PriceOtherItem = 3.45;
const double TaxRate = 5.75; // 5.75%
// Basic information about an order
string customerName, homePhone;
DateTime orderDate = new DateTime();
// Unsigned numbers to represent cleaning items
ushort numberOfShirts = 0, numberOfPants = 0, numberOfOtherItems = 0;
// Each of these sub totals will be used for cleaning items
double subTotalShirts, subTotalPants, subTotalOtherItems;
// Values used to process an order
double totalOrder, taxAmount, salesTotal;
double amountTended = 0, moneyChange;
Console.Title = "Georgetown Dry Cleaning Services";
Console.WriteLine("===============================================");
Console.WriteLine("-/- Georgetown Dry Cleaning Services -/-");
Console.WriteLine("==============================================");
// Request order information from the user
Console.Write("Enter Customer Name: ");
customerName = Console.ReadLine();
Console.Write("Enter Customer Phone: ");
homePhone = Console.ReadLine();
Console.Write("Enter the order date (mm/dd/yyyy): ");
try
{
orderDate = DateTime.Parse(Console.ReadLine());
}
catch(FormatException fexc)
{
Console.BackgroundColor = ConsoleColor.DarkBlue;
Console.ForegroundColor = ConsoleColor.Cyan;
Console.WriteLine(fexc.Message);
}
Console.ResetColor();
// Request the quantity of each category of items
try
{
Console.Write("Number of Shirts: ");
numberOfShirts = ushort.Parse(Console.ReadLine());
}
catch(FormatException)
{
Console.WriteLine("The value you typed for the number of " +
"shirts is not a valid number.");
}
try
{
Console.Write("Number of Pants: ");
numberOfPants = ushort.Parse(Console.ReadLine());
}
catch (FormatException)
{
Console.WriteLine("The value you typed for the number of " +
"pants is not a valid number.");
}
try
{
Console.Write("Number of Other Items: ");
numberOfOtherItems = ushort.Parse(Console.ReadLine());
}
catch (FormatException)
{
Console.WriteLine("The value you typed for the number of " +
"other types of items is not a valid number.");
}
// Perform the necessary calculations
subTotalShirts = numberOfShirts * PriceOneShirt;
subTotalPants = numberOfPants * PriceAPairOfPants;
subTotalOtherItems = numberOfOtherItems * PriceOtherItem;
// Calculate the "temporary" total of the order
totalOrder = subTotalShirts + subTotalPants + subTotalOtherItems;
// Calculate the tax amount using a constant rate
taxAmount = totalOrder * TaxRate / 100.00;
// Add the tax amount to the total order
salesTotal = totalOrder + taxAmount;
Console.WriteLine("-----------------------------------------");
// Communicate the total to the user...
Console.WriteLine("The Total order is: {0:C}", salesTotal);
// and request money for the order
try
{
Console.Write("Amount Tended? ");
amountTended = double.Parse(Console.ReadLine());
}
catch (FormatException)
{
Console.WriteLine("You were asked to enter an amount of money but something bad happened.");
}
// Calculate the difference owed to the customer
// or that the customer still owes to the store
moneyChange = amountTended - salesTotal;
Console.Clear();
Console.Title = "Georgetown Dry Cleaning Services";
// Display the receipt
Console.WriteLine("=========================================");
Console.WriteLine("-/- Georgetown Dry Cleaning Services -/-");
Console.WriteLine("=========================================");
Console.WriteLine("Customer: {0}", customerName);
Console.WriteLine("Home Phone: {0}", homePhone);
Console.WriteLine("Order Date: {0}", orderDate);
Console.WriteLine("-----------------------------------------");
Console.WriteLine("Item Type Qty Unit/Price Sub-Total");
Console.WriteLine("-----------------------------------------");
Console.WriteLine("Shirts{0,9} {1:C} {2:C}",
numberOfShirts, PriceOneShirt, subTotalShirts);
Console.WriteLine("Pants{0,10} {1:C} {2:C}",
numberOfPants, PriceAPairOfPants, subTotalPants);
Console.WriteLine("Other Items{0,4} {1:C} {2:C}",
numberOfOtherItems, PriceOtherItem, subTotalOtherItems);
Console.WriteLine("-----------------------------------------");
Console.WriteLine("Total Order: {0:C}", totalOrder);
Console.WriteLine("Tax Rate: {0:P}", TaxRate / 100);
Console.WriteLine("Tax Amount: {0:C}", taxAmount);
Console.WriteLine("Net Price: {0:C}", salesTotal);
Console.WriteLine("-----------------------------------------");
Console.WriteLine("Amount Tended: {0:C}", amountTended);
Console.WriteLine("Difference: {0:C}", moneyChange);
Console.WriteLine("=========================================");
return 0;
}
}
}=============================================== -/- Georgetown Dry Cleaning Services -/- ============================================== Enter Customer Name:
=============================================== -/- Georgetown Dry Cleaning Services -/- ============================================== Enter Customer Name: Catherine Richarson Enter Customer Phone: (202) 184-9738 Enter the order date (mm/dd/yyyy): 27 Mais 2019 The string was not recognized as a valid DateTime. There is an unknown word star ting at index 3. Number of Shirts: 8 Number of Pants: 12 Number of Other Items: 14 ----------------------------------------- The Total order is: $88.94 Amount Tended? 90
========================================= -/- Georgetown Dry Cleaning Services -/- ========================================= Customer: Catherine Richarson Home Phone: (202) 184-9738 Order Date: 1/1/1900 12:00:00 AM ----------------------------------------- Item Type Qty Unit/Price Sub-Total ----------------------------------------- Shirts 8 $1.25 $10.00 Pants 12 $2.15 $25.80 Other Items 14 $3.45 $48.30 ----------------------------------------- Total Order: $84.10 Tax Rate: 5.75 % Tax Amount: $4.84 Net Price: $88.94 ----------------------------------------- Amount Tended: $90.00 Difference: $1.06 ========================================= Press any key to continue . . .
namespace CountriesStatistics4
{
public class Region
{
public string Designation { get; set; }
public string Description { get; set; }
}
}namespace CountriesStatistics4
{
interface IAbbreviated
{
string Abbreviation { get; set; }
}
}namespace CountriesStatistics4
{
interface IGovernmentEntity
{
string Name { get; set; }
uint Area { get; }
string Capital { get; set; }
}
}using System;
namespace CountriesStatistics4
{
public class State : IAbbreviated,
IGovernmentEntity,
IComparable
{
// From the IAbbreviated interface
public string Abbreviation { get; set; }
// From the IGovernmentEntity interface
public string Name { get; set; }
public uint Area { get; set; }
public string Capital { get; set; }
// New Properties
public string StateName => Name;
public uint AreaSqrMiles => Area;
public uint AreaSqrKms { get; set; }
public Region Region { get; set; }
public int CompareTo(object stt)
{
if (stt == null)
{
return 0;
}
State other = stt as State;
if (other != null)
return StateName.CompareTo(other.StateName);
return 0;
}
}
}using System;
namespace CountriesStatistics4
{
public class Federation : State
{
public DateTime AdmissionUnionDate { get; set; }
public uint AdmissionUnionOrder { get; set; }
}
}using System;
namespace CountriesStatistics4
{
public class CountriesStatistics
{
private static void Display(Array entities)
{
Console.Clear();
Console.WriteLine(" United States of America");
Console.WriteLine("=========================================================================================================");
Console.WriteLine(" Area Admission to Union");
Console.WriteLine(" # Abbrv State Name SqrMls Km2 Date Order Capital Region");
Console.WriteLine("---------------------------------------------------------------------------------------------------------");
for (int counter = 0; counter <= entities.Length - 1; counter++)
{
Federation stt = (Federation)entities.GetValue(counter);
Console.WriteLine("{0,2} {1,2} {2} {3,6} {4,8} {5,10} {6} {7}",
counter + 1, stt.Abbreviation, stt.StateName,
stt.AreaSqrMiles, stt.AreaSqrKms, stt.AdmissionUnionDate,
stt.AdmissionUnionOrder, stt.Capital, stt.Region.Designation);
}
Console.WriteLine("=========================================================================================================");
}
public static int Main(string[] args)
{
Region[] regions = new Region[]
{
new Region() { Designation = "East North Central", Description = "The East North Central region includes the states around the Great Lakes." },
new Region() { Designation = "East South Central", Description = "The East South Central portion is one of the regions designated as the South." },
new Region() { Designation = "New England ", Description = "New England is the group of states in the North-East region. It is delimited in the North and North-East by Canada, in the East by the Atlantic Ocean, and in the South and West by the New York state." },
new Region() { Designation = "Mid-Atlantic ", Description = "Mid-Atlantic is a region situated in the south of New England. Mid-Atlantic is one of the regions defined by the Census bureau for statistical purposes." },
new Region() { Designation = "Mountain ", Description = "Like the name suggests, the Mountain region covers states known for their mountaneous characteristics. They are also covered by desertic areas." },
new Region() { Designation = "Pacific ", Description = "The Pacific region covers the costal western states plus the two non-continental states of Alaska and the Hawaiian islands. All states in this region have a coast on the Pacific Ocean." },
new Region() { Designation = "South Atlantic ", Description = "The South Atlantic region includes the states in the South-East part but also counts the Disctrict of Columbia." },
new Region() { Designation = "West North Central", Description = "The West North Central region includes the states in the Great Planes area. This reqion is divided from the East North Central part by the Mississippi River. This region is characterized by vast agricultural farms and high employment." },
new Region() { Designation = "West South Central", Description = "The West South Central part is one of the regions with (only) four states. The imposing Texas state is both the largest and the most populous state in the region." }
};
Federation[] states = new Federation[40];
states[0] = new Federation() { Abbreviation = "RI", Name = "Rhode Island ", Area = 1545, AreaSqrKms = 4002, AdmissionUnionDate = new DateTime(1790, 05, 29), AdmissionUnionOrder = 13, Capital = "Providence ", Region = regions[2] };
states[1] = new Federation() { Abbreviation = "OH", Name = "Ohio ", Area = 44_828, AreaSqrKms = 116_103, AdmissionUnionDate = new DateTime(1803, 03, 01), AdmissionUnionOrder = 17, Capital = "Columbus ", Region = regions[0] };
states[2] = new Federation() { Abbreviation = "KY", Name = "Kentucky ", Area = 40_411, AreaSqrKms = 104_665, AdmissionUnionDate = new DateTime(1792, 06, 01), AdmissionUnionOrder = 15, Capital = "Frankfort ", Region = regions[2] };
states[3] = new Federation() { Abbreviation = "IA", Name = "Iowa ", Area = 56_276, AreaSqrKms = 145_754, AdmissionUnionDate = new DateTime(1846, 12, 28), AdmissionUnionOrder = 29, Capital = "Des Moines ", Region = regions[7] };
states[4] = new Federation() { Abbreviation = "WI", Name = "Wisconsin ", Area = 65_503, AreaSqrKms = 169_653, AdmissionUnionDate = new DateTime(1848, 05, 29), AdmissionUnionOrder = 30, Capital = "Madison ", Region = regions[0] };
states[5] = new Federation() { Abbreviation = "VT", Name = "Vermont ", Area = 9615, AreaSqrKms = 24_903, AdmissionUnionDate = new DateTime(1791, 03, 04), AdmissionUnionOrder = 14, Capital = "Montpelier ", Region = regions[2] };
states[6] = new Federation() { Abbreviation = "ID", Name = "Idaho ", Area = 83_574, AreaSqrKms = 216_456, AdmissionUnionDate = new DateTime(1890, 07, 03), AdmissionUnionOrder = 43, Capital = "Boise ", Region = regions[4] };
states[7] = new Federation() { Abbreviation = "ME", Name = "Maine ", Area = 35_387, AreaSqrKms = 91_653, AdmissionUnionDate = new DateTime(1820, 03, 15), AdmissionUnionOrder = 23, Capital = "Augusta ", Region = regions[2] };
states[8] = new Federation() { Abbreviation = "OR", Name = "Oregon ", Area = 98_386, AreaSqrKms = 254_819, AdmissionUnionDate = new DateTime(1859, 02, 14), AdmissionUnionOrder = 33, Capital = "Salem ", Region = regions[5] };
states[9] = new Federation() { Abbreviation = "ND", Name = "North Dakota ", Area = 70_704, AreaSqrKms = 183_123, AdmissionUnionDate = new DateTime(1889, 11, 02), AdmissionUnionOrder = 39, Capital = "Bismarck ", Region = regions[7] };
states[10] = new Federation() { Abbreviation = "IN", Name = "Indiana ", Area = 36_420, AreaSqrKms = 94_328, AdmissionUnionDate = new DateTime(1816, 12, 11), AdmissionUnionOrder = 19, Capital = "Indianapolis ", Region = regions[0] };
states[11] = new Federation() { Abbreviation = "MS", Name = "Mississippi ", Area = 48_434, AreaSqrKms = 125_443, AdmissionUnionDate = new DateTime(1817, 12, 10), AdmissionUnionOrder = 20, Capital = "Jackson ", Region = regions[1] };
states[12] = new Federation() { Abbreviation = "TX", Name = "Texas ", Area = 268_601, AreaSqrKms = 695_676, AdmissionUnionDate = new DateTime(1845, 12, 29), AdmissionUnionOrder = 28, Capital = "Austin ", Region = regions[8] };
states[13] = new Federation() { Abbreviation = "MT", Name = "Montana ", Area = 147_046, AreaSqrKms = 380_850, AdmissionUnionDate = new DateTime(1889, 11, 08), AdmissionUnionOrder = 41, Capital = "Helena ", Region = regions[4] };
states[14] = new Federation() { Abbreviation = "NC", Name = "North Carolina", Area = 53_821, AreaSqrKms = 139_397, AdmissionUnionDate = new DateTime(1789, 11, 21), AdmissionUnionOrder = 12, Capital = "Raleigh ", Region = regions[6] };
states[15] = new Federation() { Abbreviation = "TN", Name = "Tennessee ", Area = 42_146, AreaSqrKms = 109_158, AdmissionUnionDate = new DateTime(1796, 06, 01), AdmissionUnionOrder = 16, Capital = "Nashville ", Region = regions[1] };
states[16] = new Federation() { Abbreviation = "NE", Name = "Nebraska ", Area = 77_358, AreaSqrKms = 200_358, AdmissionUnionDate = new DateTime(1867, 03, 01), AdmissionUnionOrder = 37, Capital = "Lincoln ", Region = regions[7] };
states[17] = new Federation() { Abbreviation = "IL", Name = "Illinois ", Area = 57_918, AreaSqrKms = 150_007, AdmissionUnionDate = new DateTime(1818, 12, 03), AdmissionUnionOrder = 21, Capital = "Springfield ", Region = regions[0] };
states[18] = new Federation() { Abbreviation = "KS", Name = "Kansas ", Area = 82_282, AreaSqrKms = 213_110, AdmissionUnionDate = new DateTime(1861, 01, 29), AdmissionUnionOrder = 34, Capital = "Topeka ", Region = regions[7] };
states[19] = new Federation() { Abbreviation = "NH", Name = "New Hampshire ", Area = 9351, AreaSqrKms = 24_219, AdmissionUnionDate = new DateTime(1788, 06, 21), AdmissionUnionOrder = 9, Capital = "Concord ", Region = regions[2] };
states[20] = new Federation() { Abbreviation = "DE", Name = "Delaware ", Area = 2489, AreaSqrKms = 6447, AdmissionUnionDate = new DateTime(1787, 12, 07), AdmissionUnionOrder = 1, Capital = "Dover ", Region = regions[6] };
states[21] = new Federation() { Abbreviation = "NJ", Name = "New Jersey ", Area = 8722, AreaSqrKms = 22_590, AdmissionUnionDate = new DateTime(1787, 12, 18), AdmissionUnionOrder = 3, Capital = "Trenton ", Region = regions[3] };
states[22] = new Federation() { Abbreviation = "AK", Name = "Alaska ", Area = 656_424, AreaSqrKms = 1_700_139, AdmissionUnionDate = new DateTime(1959, 01, 03), AdmissionUnionOrder = 49, Capital = "Juneau ", Region = regions[5] };
states[23] = new Federation() { Abbreviation = "NM", Name = "New Mexico ", Area = 121_598, AreaSqrKms = 314_939, AdmissionUnionDate = new DateTime(1912, 01, 06), AdmissionUnionOrder = 47, Capital = "Santa Fe ", Region = regions[4] };
states[24] = new Federation() { Abbreviation = "NY", Name = "New York ", Area = 54_475, AreaSqrKms = 141_089, AdmissionUnionDate = new DateTime(1788, 07, 26), AdmissionUnionOrder = 11, Capital = "Albany ", Region = regions[3] };
states[25] = new Federation() { Abbreviation = "CA", Name = "California ", Area = 163_707, AreaSqrKms = 424_002, AdmissionUnionDate = new DateTime(1850, 09, 09), AdmissionUnionOrder = 31, Capital = "Sacramento ", Region = regions[5] };
states[26] = new Federation() { Abbreviation = "MO", Name = "Missouri ", Area = 69_709, AreaSqrKms = 180_546, AdmissionUnionDate = new DateTime(1821, 08, 10), AdmissionUnionOrder = 24, Capital = "Jefferson City", Region = regions[7] };
states[27] = new Federation() { Abbreviation = "OK", Name = "Oklahoma ", Area = 69_903, AreaSqrKms = 181_049, AdmissionUnionDate = new DateTime(1907, 11, 16), AdmissionUnionOrder = 46, Capital = "Oklahoma City ", Region = regions[8] };
states[28] = new Federation() { Abbreviation = "PA", Name = "Pennsylvania ", Area = 46_058, AreaSqrKms = 119_291, AdmissionUnionDate = new DateTime(1787, 12, 12), AdmissionUnionOrder = 2, Capital = "Harrisburg ", Region = regions[3] };
states[29] = new Federation() { Abbreviation = "SC", Name = "South Carolina", Area = 32_007, AreaSqrKms = 82_898, AdmissionUnionDate = new DateTime(1788, 05, 23), AdmissionUnionOrder = 8, Capital = "Columbia ", Region = regions[6] };
states[30] = new Federation() { Abbreviation = "WY", Name = "Wyoming ", Area = 97_818, AreaSqrKms = 253_349, AdmissionUnionDate = new DateTime(1890, 07, 10), AdmissionUnionOrder = 44, Capital = "Cheyenne ", Region = regions[4] };
states[31] = new Federation() { Abbreviation = "SD", Name = "South Dakota ", Area = 77_122, AreaSqrKms = 199_745, AdmissionUnionDate = new DateTime(1889, 11, 02), AdmissionUnionOrder = 40, Capital = "Pierre ", Region = regions[7] };
states[32] = new Federation() { Abbreviation = "UT", Name = "Utah ", Area = 84_904, AreaSqrKms = 219_902, AdmissionUnionDate = new DateTime(1896, 01, 04), AdmissionUnionOrder = 45, Capital = "Salt Lake City", Region = regions[4] };
states[33] = new Federation() { Abbreviation = "AL", Name = "Alabama ", Area = 52_423, AreaSqrKms = 135_775, AdmissionUnionDate = new DateTime(1819, 12, 14), AdmissionUnionOrder = 22, Capital = "Montgomery ", Region = regions[1] };
states[34] = new Federation() { Abbreviation = "VT", Name = "Vermont ", Area = 9615, AreaSqrKms = 24_903, AdmissionUnionDate = new DateTime(1791, 03, 04), AdmissionUnionOrder = 14, Capital = "Montpelier ", Region = regions[2] };
states[35] = new Federation() { Abbreviation = "AR", Name = "Arkansas ", Area = 53_182, AreaSqrKms = 137_742, AdmissionUnionDate = new DateTime(1836, 06, 15), AdmissionUnionOrder = 25, Capital = "Little Rock ", Region = regions[8] };
states[36] = new Federation() { Abbreviation = "WA", Name = "Washington ", Area = 71_303, AreaSqrKms = 184_674, AdmissionUnionDate = new DateTime(1889, 11, 11), AdmissionUnionOrder = 42, Capital = "Olympia ", Region = regions[5] };
states[37] = new Federation() { Abbreviation = "AZ", Name = "Arizona ", Area = 114_006, AreaSqrKms = 295_276, AdmissionUnionDate = new DateTime(1912, 02, 14), AdmissionUnionOrder = 48, Capital = "Phoenix ", Region = regions[4] };
states[38] = new Federation() { Abbreviation = "WV", Name = "West Virginia ", Area = 24_231, AreaSqrKms = 62_759, AdmissionUnionDate = new DateTime(1863, 06, 20), AdmissionUnionOrder = 35, Capital = "Charleston ", Region = regions[6] };
states[39] = new Federation() { Abbreviation = "LA", Name = "Louisiana ", Area = 51_844, AreaSqrKms = 134_275, AdmissionUnionDate = new DateTime(1812, 04, 30), AdmissionUnionOrder = 18, Capital = "Baton Rouge ", Region = regions[8] };
Array.Resize(ref states, states.Length + 5);
states[40] = new Federation() { Abbreviation = "MA", Name = "Massachusetts ", Area = 10_555, AreaSqrKms = 27_337, AdmissionUnionDate = new DateTime(1788, 02, 06), AdmissionUnionOrder = 6, Capital = "Boston ", Region = regions[2] };
states[41] = new Federation() { Abbreviation = "FL", Name = "Florida ", Area = 65_758, AreaSqrKms = 170_313, AdmissionUnionDate = new DateTime(1845, 03, 03), AdmissionUnionOrder = 27, Capital = "Tallahassee ", Region = regions[6] };
states[42] = new Federation() { Abbreviation = "GA", Name = "Georgia ", Area = 59_441, AreaSqrKms = 153_953, AdmissionUnionDate = new DateTime(1788, 01, 02), AdmissionUnionOrder = 4, Capital = "Atlanta ", Region = regions[6] };
states[43] = new Federation() { Abbreviation = "HI", Name = "Hawaii ", Area = 10_932, AreaSqrKms = 28_313, AdmissionUnionDate = new DateTime(1959, 08, 21), AdmissionUnionOrder = 50, Capital = "Honolulu ", Region = regions[5] };
states[44] = new Federation() { Abbreviation = "MD", Name = "Maryland ", Area = 12_407, AreaSqrKms = 32_135, AdmissionUnionDate = new DateTime(1788, 04, 28), AdmissionUnionOrder = 7, Capital = "Annapolis ", Region = regions[6] };
Federation[] temporary = new Federation[states.Length + 5];
Array.Copy(states, temporary, states.Length);
states = temporary;
states[45] = new Federation() { Abbreviation = "CO", Name = "Colorado ", Area = 104_100, AreaSqrKms = 269_620, AdmissionUnionDate = new DateTime(1876, 08, 01), AdmissionUnionOrder = 38, Capital = "Denver ", Region = regions[4] };
states[46] = new Federation() { Abbreviation = "MI", Name = "Michigan ", Area = 98_810, AreaSqrKms = 250_738, AdmissionUnionDate = new DateTime(1837, 01, 26), AdmissionUnionOrder = 26, Capital = "Lansing ", Region = regions[0] };
states[47] = new Federation() { Abbreviation = "MN", Name = "Minnesota ", Area = 86_943, AreaSqrKms = 225_182, AdmissionUnionDate = new DateTime(1858, 05, 11), AdmissionUnionOrder = 32, Capital = "Saint Paul ", Region = regions[7] };
states[48] = new Federation() { Abbreviation = "CT", Name = "Connecticut ", Area = 5544, AreaSqrKms = 14_358, AdmissionUnionDate = new DateTime(1788, 01, 09), AdmissionUnionOrder = 5, Capital = "Hartford ", Region = regions[3] };
states[49] = new Federation() { Abbreviation = "NV", Name = "Nevada ", Area = 110_567, AreaSqrKms = 286_368, AdmissionUnionDate = new DateTime(1864, 10, 31), AdmissionUnionOrder = 36, Capital = "Frankfort ", Region = regions[4] };
Display(states);
Console.Write("Do you want to sort the list in alphabetical order (y/n)? ");
string answer = Console.ReadLine();
if (answer.ToLower().Equals("y"))
{
Array.Sort(states);
Display(states);
}
else
{
Console.WriteLine("Good Bye!!!");
Console.WriteLine("====================================================================================================");
}
return 0;
}
}
} United States of America
=========================================================================================================
Area Admission to Union
# Abbrv State Name SqrMls Km2 Date Order Capital Region
---------------------------------------------------------------------------------------------------------
1 RI Rhode Island 1545 4002 5/29/1790 12:00:00 AM 13 Providence
2 OH Ohio 44828 116103 3/1/1803 12:00:00 AM 17 Columbus
3 KY Kentucky 40411 104665 6/1/1792 12:00:00 AM 15 Frankfort
4 IA Iowa 56276 145754 12/28/1846 12:00:00 AM 29 Des Moines
5 WI Wisconsin 65503 169653 5/29/1848 12:00:00 AM 30 Madison
6 VT Vermont 9615 24903 3/4/1791 12:00:00 AM 14 Montpelier
7 ID Idaho 83574 216456 7/3/1890 12:00:00 AM 43 Boise
8 ME Maine 35387 91653 3/15/1820 12:00:00 AM 23 Augusta
9 OR Oregon 98386 254819 2/14/1859 12:00:00 AM 33 Salem
10 ND North Dakota 70704 183123 11/2/1889 12:00:00 AM 39 Bismarck
11 IN Indiana 36420 94328 12/11/1816 12:00:00 AM 19 Indianapolis
12 MS Mississippi 48434 125443 12/10/1817 12:00:00 AM 20 Jackson
13 TX Texas 268601 695676 12/29/1845 12:00:00 AM 28 Austin
14 MT Montana 147046 380850 11/8/1889 12:00:00 AM 41 Helena
15 NC North Carolina 53821 139397 11/21/1789 12:00:00 AM 12 Raleigh
16 TN Tennessee 42146 109158 6/1/1796 12:00:00 AM 16 Nashville
17 NE Nebraska 77358 200358 3/1/1867 12:00:00 AM 37 Lincoln
18 IL Illinois 57918 150007 12/3/1818 12:00:00 AM 21 Springfield
19 KS Kansas 82282 213110 1/29/1861 12:00:00 AM 34 Topeka
20 NH New Hampshire 9351 24219 6/21/1788 12:00:00 AM 9 Concord
21 DE Delaware 2489 6447 12/7/1787 12:00:00 AM 1 Dover
22 NJ New Jersey 8722 22590 12/18/1787 12:00:00 AM 3 Trenton
23 AK Alaska 656424 1700139 1/3/1959 12:00:00 AM 49 Juneau
24 NM New Mexico 121598 314939 1/6/1912 12:00:00 AM 47 Santa Fe
25 NY New York 54475 141089 7/26/1788 12:00:00 AM 11 Albany
26 CA California 163707 424002 9/9/1850 12:00:00 AM 31 Sacramento
27 MO Missouri 69709 180546 8/10/1821 12:00:00 AM 24 Jefferson City
28 OK Oklahoma 69903 181049 11/16/1907 12:00:00 AM 46 Oklahoma City
29 PA Pennsylvania 46058 119291 12/12/1787 12:00:00 AM 2 Harrisburg
30 SC South Carolina 32007 82898 5/23/1788 12:00:00 AM 8 Columbia
31 WY Wyoming 97818 253349 7/10/1890 12:00:00 AM 44 Cheyenne
32 SD South Dakota 77122 199745 11/2/1889 12:00:00 AM 40 Pierre
33 UT Utah 84904 219902 1/4/1896 12:00:00 AM 45 Salt Lake City
34 AL Alabama 52423 135775 12/14/1819 12:00:00 AM 22 Montgomery
35 VT Vermont 9615 24903 3/4/1791 12:00:00 AM 14 Montpelier
36 AR Arkansas 53182 137742 6/15/1836 12:00:00 AM 25 Little Rock
37 WA Washington 71303 184674 11/11/1889 12:00:00 AM 42 Olympia
38 AZ Arizona 114006 295276 2/14/1912 12:00:00 AM 48 Phoenix
39 WV West Virginia 24231 62759 6/20/1863 12:00:00 AM 35 Charleston
40 LA Louisiana 51844 134275 4/30/1812 12:00:00 AM 18 Baton Rouge
41 MA Massachusetts 10555 27337 2/6/1788 12:00:00 AM 6 Boston
42 FL Florida 65758 170313 3/3/1845 12:00:00 AM 27 Tallahassee
43 GA Georgia 59441 153953 1/2/1788 12:00:00 AM 4 Atlanta
44 HI Hawaii 10932 28313 8/21/1959 12:00:00 AM 50 Honolulu
45 MD Maryland 12407 32135 4/28/1788 12:00:00 AM 7 Annapolis
46 CO Colorado 104100 269620 8/1/1876 12:00:00 AM 38 Denver
47 MI Michigan 98810 250738 1/26/1837 12:00:00 AM 26 Lansing
48 MN Minnesota 86943 225182 5/11/1858 12:00:00 AM 32 Saint Paul
49 CT Connecticut 5544 14358 1/9/1788 12:00:00 AM 5 Hartford
50 NV Nevada 110567 286368 10/31/1864 12:00:00 AM 36 Frankfort
=========================================================================================================
Do you want to sort the list in alphabetical order (y/n)?Converting a String to Date
Before displaying a DateTime value in your application, you can first convert it to a string. To support this, the DateTime structure provides the ToString() method that is overloaded with various versions. One of the versions takes no argument and its syntax is:
public override string ToString();
If you call this version of the method, the compiler uses a default format depending on the language set on the user's computer. If you want to control how the date should be rendered, you can use the version of the ToString() method that takes as argument a String value.
Introduction to Data Formatting
As mentioned earlier, when the user enters a date value for a DateTime variable, the compiler adds a time part to the value. Fortunately, if you want to consider only the date or only the time part, you can specify this to the compiler. To support this, the DateTime data type provides a series of letters you can use to format how its value should be displayed to the user. The character is entered in the placeholder of the DateTime variable after the 0 or the incremental numeric value.
Practical Learning: Controlling Date Formatting
using System;
namespace GeorgetownDryCleaningServices
{
class GeorgetownDryCleaningServices
{
public static int Main(string[] args)
{
. . . No Change
Console.Clear();
Console.Title = "Georgetown Dry Cleaning Services";
// Display the receipt
Console.WriteLine("=========================================");
Console.WriteLine("-/- Georgetown Dry Cleaning Services -/-");
Console.WriteLine("=========================================");
Console.WriteLine("Customer: {0}", customerName);
Console.WriteLine("Home Phone: {0}", homePhone);
Console.WriteLine("Order Date: {0:D}", orderDate);
Console.WriteLine("-----------------------------------------");
Console.WriteLine("Item Type Qty Unit/Price Sub-Total");
. . . No Change
return 0;
}
}
}=============================================== -/- Georgetown Dry Cleaning Services -/- ============================================== Enter Customer Name: Catherine Richardson Enter Customer Phone: (202) 184-9738 Enter the order date (mm/dd/yyyy): 27 May 2019 Number of Shirts: 8 Number of Pants: 12 Number of Other Items: 14 ----------------------------------------- The Total order is: $88.94 Amount Tended? 90
========================================= -/- Georgetown Dry Cleaning Services -/- ========================================= Customer: Catherine Richardson Home Phone: (202) 184-9738 Order Date: Monday, May 27, 2019 ----------------------------------------- Item Type Qty Unit/Price Sub-Total ----------------------------------------- Shirts 8 $1.25 $10.00 Pants 12 $2.15 $25.80 Other Items 14 $3.45 $48.30 ----------------------------------------- Total Order: $84.10 Tax Rate: 5.75 % Tax Amount: $4.84 Net Price: $88.94 ----------------------------------------- Amount Tended: $90.00 Difference: $1.06 ========================================= Press any key to continue . . .
Rules of Date Formats
The computer uses two main categories of date display. These categories are based on the language used by your computer. For example, most user computers that reside in the United States use a standard known as US English. This commands how the date displays in the continental US. Each category uses specific characters to represent its value:
| Format | Description |
| MM | The double M (in uppercase) string gets the numeric value of the month from 1 to 12. If the number is less than 10, it would display with the leading 0. Here is an example: using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2002, 4, 22);
string strMonth = date.ToString("MM");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Month Value: {0}\n", strMonth);
return 0;
}
}
}
This would produce: Date and Time: 4/22/2002 12:00:00 AM
Month Value: 04
Press any key to continue . . .
It the number is higher than 9, it would display so. |
| MMM | The triple M as MMM (in uppercase) gets the name of the month using three letters. This variable is defined by the operating system. The names of the month in US English are Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, and Dec. Here is an example: using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(1998, 1, 12);
string strMonth = date.ToString("MMM");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Month Name: {0}\n", strMonth);
return 0;
}
}
}
This would produce: Date and Time: 1/12/1998 12:00:00 AM
Month Name: Jan
Press any key to continue . . .
|
| MMMM | The quadruple M as MMMM (in uppercase) gets the complete name of a month as defined by the operating system of the user's computer. The names of the months are January, February, March, April, May, June, July, August, September, October, November, and December. Here is an example: using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2004, 10, 23);
string strMonth = date.ToString("MMMM");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Month Name: {0}\n", strMonth);
return 0;
}
}
}
This would produce: Date and Time: 10/23/2004 12:00:00 AM
Month Name: October
Press any key to continue . . .
|
| dd | The double d gets the numeric day of the
month. If the number is less than 10, it would display with a leading
0. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2002, 4, 2);
string strDay = date.ToString("dd");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Month Value: {0}\n", strDay);
return 0;
}
}
}
This would display: Date and Time: 4/2/2002 12:00:00 AM
Month Value: 02
Press any key to continue . . .
|
| yy | The double y is used to
get the numeric year with the last two
digits. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2002, 4, 2);
string strYear2Digits = date.ToString("yy");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Year Value: {0}\n", strYear2Digits);
return 0;
}
}
}
This would produce: Date and Time: 4/2/2002 12:00:00 AM
Year Value: 02
Press any key to continue . . .
|
| yyyy | The yyyy string is used to get all four digits of a
year. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2002, 4, 2);
string strYear4Digits = date.ToString("yyyy");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Year Value: {0}\n", strYear4Digits);
return 0;
}
}
}
This would produce: Date and Time: 4/2/2002 12:00:00 AM
Year Value: 2002
Press any key to continue . . .
If the year was provided with two digits, such as 98, it would still be produced with 4 digits. Consider the following example: using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(98, 4, 2);
string strYear4Digits = date.ToString("yyyy");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Year Value: {0}\n", strYear4Digits);
return 0;
}
}
}
This would produce: Date and Time: 4/2/0098 12:00:00 AM
Year Value: 0098
Press any key to continue . . .
Notice that this may be a wrong date. For this reason, in your C# applications, you should always make it a habit to (always) provide your years with 4 digits. |
Date Formats
The Computer's System of Displaying Dates
To display a date in an application, by default, the compiler checks the Regional Options of the Control Panel. To see the options, from the Control Panel, you can double-click Regional or Language Option. From the Regional Options tab of the Regional or Language Option dialog box, you can click Customize... In the Customize Regional Options dialog box, click Date.
Getting a Date Value From a DateTime Object
You may have notice that, by default, a DateTime object always produces both a date and a time. In some cases, you will be interested in only the date portion of the object. To get a date value, you can call the DateTime.ToString() method that takes a String as argument and apply some rules:
| Format | Description |
| Empty Space: Between
the components of a date value, you are allowed to leave empty
spaces if you want. Don't pass an empty space to the ToString() method. |
|
| , | Comma: To separate the
sections of a date value, you can use the comma. Don't pass a comma by itself to the ToString() method. |
| / | Date Separator: The
compiler refers to the Control Panel to identify this character. In
US English, the forward slash is used to separate the portions of a
date:
Don't pass the forward slash by itself to the ToString() method. |
| Others: - . | Dash and Others: Besides the
forward slash, the user's computer may allow other characters. For
example, in US English, the "-" can be used. You can check
available characters in the Date Separator combo box of the Date tab
of the Customize Regional Options of the Control Panel. Don't pass any of these characters by itself to the ToString() method. |
The other characters and their combinations (MM, MMM, MMMM, dd, yy, and yyyy) are used as we reviewed them.
Here are examples of displaying date formats:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2004, 10, 23);
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine(date.ToString("M/d/yyyy"));
Console.WriteLine(date.ToString("M/d/yy"));
Console.WriteLine(date.ToString("MM/dd/yy"));
Console.WriteLine(date.ToString("MM/dd/yyyy"));
Console.WriteLine(date.ToString("yy/MM/dd"));
Console.WriteLine(date.ToString("yyyy-MM-dd"));
Console.WriteLine(date.ToString("dd-MMM-yy"));
return 0;
}
}
}
This would produce:
10/15/2006 10/15/06 10/15/06 10/15/2006 06/10/15 2006-10-15 15-Oct-06 Press any key to continue . . .
The Short Date
Instead of creating your own format, the Microsoft Windows operating system provide two names that can be used to identify a date. A date is referred to as short if it includes (only) the numeric portions of the month and the day of a date value. The operating systems follows the rules we have reviewed so far for the numbers and the Date Separator. The possible formats of a short date can be seen in the Short Date Format combo box of the Date tab of the Customize Regional Options of the Regional and Language Settings of the Control Panel:
To get the Short Date of a DateTime object, pass a "d" (one d in lowercase) string to the ToString() method. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2004, 10, 23);
string strDate = date.ToString("d");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Date Portion: {0}\n", strDate);
return 0;
}
}
}
This would produce:
Date and Time: 10/23/2004 12:00:00 AM Date Portion: 10/23/2004 Press any key to continue . . .
To support short date formats, the DateTime structure is equipped with a method named ToShortDateString. Its syntax is:
public string ToShortDateString();
Practical Learning: Getting a Short Date String
using System;
namespace CountriesStatistics4
{
public class CountriesStatistics
{
private static void Display(Array entities)
{
Console.Clear();
Console.WriteLine(" United States of America");
Console.WriteLine("=========================================================================================================");
Console.WriteLine(" Area Admission to Union");
Console.WriteLine(" # Abbrv State Name SqrMls Km2 Date Order Capital Region");
Console.WriteLine("---------------------------------------------------------------------------------------------------------");
for (int counter = 0; counter <= entities.Length - 1; counter++)
{
Federation stt = (Federation)entities.GetValue(counter);
Console.WriteLine("{0,2} {1,2} {2} {3,6} {4,8} {5,10} {6,3} {7} {8}",
counter + 1, stt.Abbreviation, stt.StateName,
stt.AreaSqrMiles, stt.AreaSqrKms, stt.AdmissionUnionDate.ToShortDateString(),
stt.AdmissionUnionOrder, stt.Capital, stt.Region.Designation);
}
Console.WriteLine("=========================================================================================================");
}
public static int Main(string[] args)
{
Region[] regions = new Region[]
{
new Region() { Designation = "East North Central", Description = "The East North Central region includes the states around the Great Lakes." },
new Region() { Designation = "East South Central", Description = "The East South Central portion is one of the regions designated as the South." },
new Region() { Designation = "New England ", Description = "New England is the group of states in the North-East region. It is delimited in the North and North-East by Canada, in the East by the Atlantic Ocean, and in the South and West by the New York state." },
new Region() { Designation = "Mid-Atlantic ", Description = "Mid-Atlantic is a region situated in the south of New England. Mid-Atlantic is one of the regions defined by the Census bureau for statistical purposes." },
new Region() { Designation = "Mountain ", Description = "Like the name suggests, the Mountain region covers states known for their mountaneous characteristics. They are also covered by desertic areas." },
new Region() { Designation = "Pacific ", Description = "The Pacific region covers the costal western states plus the two non-continental states of Alaska and the Hawaiian islands. All states in this region have a coast on the Pacific Ocean." },
new Region() { Designation = "South Atlantic ", Description = "The South Atlantic region includes the states in the South-East part but also counts the Disctrict of Columbia." },
new Region() { Designation = "West North Central", Description = "The West North Central region includes the states in the Great Planes area. This reqion is divided from the East North Central part by the Mississippi River. This region is characterized by vast agricultural farms and high employment." },
new Region() { Designation = "West South Central", Description = "The West South Central part is one of the regions with (only) four states. The imposing Texas state is both the largest and the most populous state in the region." }
};
Federation[] states = new Federation[40];
states[0] = new Federation() { Abbreviation = "RI", Name = "Rhode Island ", Area = 1545, AreaSqrKms = 4002, AdmissionUnionDate = new DateTime(1790, 05, 29), AdmissionUnionOrder = 13, Capital = "Providence ", Region = regions[2] };
states[1] = new Federation() { Abbreviation = "OH", Name = "Ohio ", Area = 44_828, AreaSqrKms = 116_103, AdmissionUnionDate = new DateTime(1803, 03, 01), AdmissionUnionOrder = 17, Capital = "Columbus ", Region = regions[0] };
states[2] = new Federation() { Abbreviation = "KY", Name = "Kentucky ", Area = 40_411, AreaSqrKms = 104_665, AdmissionUnionDate = new DateTime(1792, 06, 01), AdmissionUnionOrder = 15, Capital = "Frankfort ", Region = regions[2] };
states[3] = new Federation() { Abbreviation = "IA", Name = "Iowa ", Area = 56_276, AreaSqrKms = 145_754, AdmissionUnionDate = new DateTime(1846, 12, 28), AdmissionUnionOrder = 29, Capital = "Des Moines ", Region = regions[7] };
states[4] = new Federation() { Abbreviation = "WI", Name = "Wisconsin ", Area = 65_503, AreaSqrKms = 169_653, AdmissionUnionDate = new DateTime(1848, 05, 29), AdmissionUnionOrder = 30, Capital = "Madison ", Region = regions[0] };
states[5] = new Federation() { Abbreviation = "VT", Name = "Vermont ", Area = 9615, AreaSqrKms = 24_903, AdmissionUnionDate = new DateTime(1791, 03, 04), AdmissionUnionOrder = 14, Capital = "Montpelier ", Region = regions[2] };
states[6] = new Federation() { Abbreviation = "ID", Name = "Idaho ", Area = 83_574, AreaSqrKms = 216_456, AdmissionUnionDate = new DateTime(1890, 07, 03), AdmissionUnionOrder = 43, Capital = "Boise ", Region = regions[4] };
states[7] = new Federation() { Abbreviation = "ME", Name = "Maine ", Area = 35_387, AreaSqrKms = 91_653, AdmissionUnionDate = new DateTime(1820, 03, 15), AdmissionUnionOrder = 23, Capital = "Augusta ", Region = regions[2] };
states[8] = new Federation() { Abbreviation = "OR", Name = "Oregon ", Area = 98_386, AreaSqrKms = 254_819, AdmissionUnionDate = new DateTime(1859, 02, 14), AdmissionUnionOrder = 33, Capital = "Salem ", Region = regions[5] };
states[9] = new Federation() { Abbreviation = "ND", Name = "North Dakota ", Area = 70_704, AreaSqrKms = 183_123, AdmissionUnionDate = new DateTime(1889, 11, 02), AdmissionUnionOrder = 39, Capital = "Bismarck ", Region = regions[7] };
states[10] = new Federation() { Abbreviation = "IN", Name = "Indiana ", Area = 36_420, AreaSqrKms = 94_328, AdmissionUnionDate = new DateTime(1816, 12, 11), AdmissionUnionOrder = 19, Capital = "Indianapolis ", Region = regions[0] };
states[11] = new Federation() { Abbreviation = "MS", Name = "Mississippi ", Area = 48_434, AreaSqrKms = 125_443, AdmissionUnionDate = new DateTime(1817, 12, 10), AdmissionUnionOrder = 20, Capital = "Jackson ", Region = regions[1] };
states[12] = new Federation() { Abbreviation = "TX", Name = "Texas ", Area = 268_601, AreaSqrKms = 695_676, AdmissionUnionDate = new DateTime(1845, 12, 29), AdmissionUnionOrder = 28, Capital = "Austin ", Region = regions[8] };
states[13] = new Federation() { Abbreviation = "MT", Name = "Montana ", Area = 147_046, AreaSqrKms = 380_850, AdmissionUnionDate = new DateTime(1889, 11, 08), AdmissionUnionOrder = 41, Capital = "Helena ", Region = regions[4] };
states[14] = new Federation() { Abbreviation = "NC", Name = "North Carolina", Area = 53_821, AreaSqrKms = 139_397, AdmissionUnionDate = new DateTime(1789, 11, 21), AdmissionUnionOrder = 12, Capital = "Raleigh ", Region = regions[6] };
states[15] = new Federation() { Abbreviation = "TN", Name = "Tennessee ", Area = 42_146, AreaSqrKms = 109_158, AdmissionUnionDate = new DateTime(1796, 06, 01), AdmissionUnionOrder = 16, Capital = "Nashville ", Region = regions[1] };
states[16] = new Federation() { Abbreviation = "NE", Name = "Nebraska ", Area = 77_358, AreaSqrKms = 200_358, AdmissionUnionDate = new DateTime(1867, 03, 01), AdmissionUnionOrder = 37, Capital = "Lincoln ", Region = regions[7] };
states[17] = new Federation() { Abbreviation = "IL", Name = "Illinois ", Area = 57_918, AreaSqrKms = 150_007, AdmissionUnionDate = new DateTime(1818, 12, 03), AdmissionUnionOrder = 21, Capital = "Springfield ", Region = regions[0] };
states[18] = new Federation() { Abbreviation = "KS", Name = "Kansas ", Area = 82_282, AreaSqrKms = 213_110, AdmissionUnionDate = new DateTime(1861, 01, 29), AdmissionUnionOrder = 34, Capital = "Topeka ", Region = regions[7] };
states[19] = new Federation() { Abbreviation = "NH", Name = "New Hampshire ", Area = 9351, AreaSqrKms = 24_219, AdmissionUnionDate = new DateTime(1788, 06, 21), AdmissionUnionOrder = 9, Capital = "Concord ", Region = regions[2] };
states[20] = new Federation() { Abbreviation = "DE", Name = "Delaware ", Area = 2489, AreaSqrKms = 6447, AdmissionUnionDate = new DateTime(1787, 12, 07), AdmissionUnionOrder = 1, Capital = "Dover ", Region = regions[6] };
states[21] = new Federation() { Abbreviation = "NJ", Name = "New Jersey ", Area = 8722, AreaSqrKms = 22_590, AdmissionUnionDate = new DateTime(1787, 12, 18), AdmissionUnionOrder = 3, Capital = "Trenton ", Region = regions[3] };
states[22] = new Federation() { Abbreviation = "AK", Name = "Alaska ", Area = 656_424, AreaSqrKms = 1_700_139, AdmissionUnionDate = new DateTime(1959, 01, 03), AdmissionUnionOrder = 49, Capital = "Juneau ", Region = regions[5] };
states[23] = new Federation() { Abbreviation = "NM", Name = "New Mexico ", Area = 121_598, AreaSqrKms = 314_939, AdmissionUnionDate = new DateTime(1912, 01, 06), AdmissionUnionOrder = 47, Capital = "Santa Fe ", Region = regions[4] };
states[24] = new Federation() { Abbreviation = "NY", Name = "New York ", Area = 54_475, AreaSqrKms = 141_089, AdmissionUnionDate = new DateTime(1788, 07, 26), AdmissionUnionOrder = 11, Capital = "Albany ", Region = regions[3] };
states[25] = new Federation() { Abbreviation = "CA", Name = "California ", Area = 163_707, AreaSqrKms = 424_002, AdmissionUnionDate = new DateTime(1850, 09, 09), AdmissionUnionOrder = 31, Capital = "Sacramento ", Region = regions[5] };
states[26] = new Federation() { Abbreviation = "MO", Name = "Missouri ", Area = 69_709, AreaSqrKms = 180_546, AdmissionUnionDate = new DateTime(1821, 08, 10), AdmissionUnionOrder = 24, Capital = "Jefferson City", Region = regions[7] };
states[27] = new Federation() { Abbreviation = "OK", Name = "Oklahoma ", Area = 69_903, AreaSqrKms = 181_049, AdmissionUnionDate = new DateTime(1907, 11, 16), AdmissionUnionOrder = 46, Capital = "Oklahoma City ", Region = regions[8] };
states[28] = new Federation() { Abbreviation = "PA", Name = "Pennsylvania ", Area = 46_058, AreaSqrKms = 119_291, AdmissionUnionDate = new DateTime(1787, 12, 12), AdmissionUnionOrder = 2, Capital = "Harrisburg ", Region = regions[3] };
states[29] = new Federation() { Abbreviation = "SC", Name = "South Carolina", Area = 32_007, AreaSqrKms = 82_898, AdmissionUnionDate = new DateTime(1788, 05, 23), AdmissionUnionOrder = 8, Capital = "Columbia ", Region = regions[6] };
states[30] = new Federation() { Abbreviation = "WY", Name = "Wyoming ", Area = 97_818, AreaSqrKms = 253_349, AdmissionUnionDate = new DateTime(1890, 07, 10), AdmissionUnionOrder = 44, Capital = "Cheyenne ", Region = regions[4] };
states[31] = new Federation() { Abbreviation = "SD", Name = "South Dakota ", Area = 77_122, AreaSqrKms = 199_745, AdmissionUnionDate = new DateTime(1889, 11, 02), AdmissionUnionOrder = 40, Capital = "Pierre ", Region = regions[7] };
states[32] = new Federation() { Abbreviation = "UT", Name = "Utah ", Area = 84_904, AreaSqrKms = 219_902, AdmissionUnionDate = new DateTime(1896, 01, 04), AdmissionUnionOrder = 45, Capital = "Salt Lake City", Region = regions[4] };
states[33] = new Federation() { Abbreviation = "AL", Name = "Alabama ", Area = 52_423, AreaSqrKms = 135_775, AdmissionUnionDate = new DateTime(1819, 12, 14), AdmissionUnionOrder = 22, Capital = "Montgomery ", Region = regions[1] };
states[34] = new Federation() { Abbreviation = "VT", Name = "Vermont ", Area = 9615, AreaSqrKms = 24_903, AdmissionUnionDate = new DateTime(1791, 03, 04), AdmissionUnionOrder = 14, Capital = "Montpelier ", Region = regions[2] };
states[35] = new Federation() { Abbreviation = "AR", Name = "Arkansas ", Area = 53_182, AreaSqrKms = 137_742, AdmissionUnionDate = new DateTime(1836, 06, 15), AdmissionUnionOrder = 25, Capital = "Little Rock ", Region = regions[8] };
states[36] = new Federation() { Abbreviation = "WA", Name = "Washington ", Area = 71_303, AreaSqrKms = 184_674, AdmissionUnionDate = new DateTime(1889, 11, 11), AdmissionUnionOrder = 42, Capital = "Olympia ", Region = regions[5] };
states[37] = new Federation() { Abbreviation = "AZ", Name = "Arizona ", Area = 114_006, AreaSqrKms = 295_276, AdmissionUnionDate = new DateTime(1912, 02, 14), AdmissionUnionOrder = 48, Capital = "Phoenix ", Region = regions[4] };
states[38] = new Federation() { Abbreviation = "WV", Name = "West Virginia ", Area = 24_231, AreaSqrKms = 62_759, AdmissionUnionDate = new DateTime(1863, 06, 20), AdmissionUnionOrder = 35, Capital = "Charleston ", Region = regions[6] };
states[39] = new Federation() { Abbreviation = "LA", Name = "Louisiana ", Area = 51_844, AreaSqrKms = 134_275, AdmissionUnionDate = new DateTime(1812, 04, 30), AdmissionUnionOrder = 18, Capital = "Baton Rouge ", Region = regions[8] };
Array.Resize(ref states, states.Length + 5);
states[40] = new Federation() { Abbreviation = "MA", Name = "Massachusetts ", Area = 10_555, AreaSqrKms = 27_337, AdmissionUnionDate = new DateTime(1788, 02, 06), AdmissionUnionOrder = 6, Capital = "Boston ", Region = regions[2] };
states[41] = new Federation() { Abbreviation = "FL", Name = "Florida ", Area = 65_758, AreaSqrKms = 170_313, AdmissionUnionDate = new DateTime(1845, 03, 03), AdmissionUnionOrder = 27, Capital = "Tallahassee ", Region = regions[6] };
states[42] = new Federation() { Abbreviation = "GA", Name = "Georgia ", Area = 59_441, AreaSqrKms = 153_953, AdmissionUnionDate = new DateTime(1788, 01, 02), AdmissionUnionOrder = 4, Capital = "Atlanta ", Region = regions[6] };
states[43] = new Federation() { Abbreviation = "HI", Name = "Hawaii ", Area = 10_932, AreaSqrKms = 28_313, AdmissionUnionDate = new DateTime(1959, 08, 21), AdmissionUnionOrder = 50, Capital = "Honolulu ", Region = regions[5] };
states[44] = new Federation() { Abbreviation = "MD", Name = "Maryland ", Area = 12_407, AreaSqrKms = 32_135, AdmissionUnionDate = new DateTime(1788, 04, 28), AdmissionUnionOrder = 7, Capital = "Annapolis ", Region = regions[6] };
Federation[] temporary = new Federation[states.Length + 5];
Array.Copy(states, temporary, states.Length);
states = temporary;
states[45] = new Federation() { Abbreviation = "CO", Name = "Colorado ", Area = 104_100, AreaSqrKms = 269_620, AdmissionUnionDate = new DateTime(1876, 08, 01), AdmissionUnionOrder = 38, Capital = "Denver ", Region = regions[4] };
states[46] = new Federation() { Abbreviation = "MI", Name = "Michigan ", Area = 98_810, AreaSqrKms = 250_738, AdmissionUnionDate = new DateTime(1837, 01, 26), AdmissionUnionOrder = 26, Capital = "Lansing ", Region = regions[0] };
states[47] = new Federation() { Abbreviation = "MN", Name = "Minnesota ", Area = 86_943, AreaSqrKms = 225_182, AdmissionUnionDate = new DateTime(1858, 05, 11), AdmissionUnionOrder = 32, Capital = "Saint Paul ", Region = regions[7] };
states[48] = new Federation() { Abbreviation = "CT", Name = "Connecticut ", Area = 5544, AreaSqrKms = 14_358, AdmissionUnionDate = new DateTime(1788, 01, 09), AdmissionUnionOrder = 5, Capital = "Hartford ", Region = regions[3] };
states[49] = new Federation() { Abbreviation = "NV", Name = "Nevada ", Area = 110_567, AreaSqrKms = 286_368, AdmissionUnionDate = new DateTime(1864, 10, 31), AdmissionUnionOrder = 36, Capital = "Frankfort ", Region = regions[4] };
Display(states);
Console.Write("Do you want to sort the list in alphabetical order (y/n)? ");
string answer = Console.ReadLine();
if (answer.ToLower().Equals("y"))
{
Array.Sort(states);
Display(states);
}
else
{
Console.WriteLine("Good Bye!!!");
Console.WriteLine("====================================================================================================");
}
return 0;
}
}
} United States of America
=========================================================================================================
Area Admission to Union
# Abbrv State Name SqrMls Km2 Date Order Capital Region
---------------------------------------------------------------------------------------------------------
1 RI Rhode Island 1545 4002 5/29/1790 13 Providence New England
2 OH Ohio 44828 116103 3/1/1803 17 Columbus East North Central
3 KY Kentucky 40411 104665 6/1/1792 15 Frankfort New England
4 IA Iowa 56276 145754 12/28/1846 29 Des Moines West North Central
5 WI Wisconsin 65503 169653 5/29/1848 30 Madison East North Central
6 VT Vermont 9615 24903 3/4/1791 14 Montpelier New England
7 ID Idaho 83574 216456 7/3/1890 43 Boise Mountain
8 ME Maine 35387 91653 3/15/1820 23 Augusta New England
9 OR Oregon 98386 254819 2/14/1859 33 Salem Pacific
10 ND North Dakota 70704 183123 11/2/1889 39 Bismarck West North Central
11 IN Indiana 36420 94328 12/11/1816 19 Indianapolis East North Central
12 MS Mississippi 48434 125443 12/10/1817 20 Jackson East South Central
13 TX Texas 268601 695676 12/29/1845 28 Austin West South Central
14 MT Montana 147046 380850 11/8/1889 41 Helena Mountain
15 NC North Carolina 53821 139397 11/21/1789 12 Raleigh South Atlantic
16 TN Tennessee 42146 109158 6/1/1796 16 Nashville East South Central
17 NE Nebraska 77358 200358 3/1/1867 37 Lincoln West North Central
18 IL Illinois 57918 150007 12/3/1818 21 Springfield East North Central
19 KS Kansas 82282 213110 1/29/1861 34 Topeka West North Central
20 NH New Hampshire 9351 24219 6/21/1788 9 Concord New England
21 DE Delaware 2489 6447 12/7/1787 1 Dover South Atlantic
22 NJ New Jersey 8722 22590 12/18/1787 3 Trenton Mid-Atlantic
23 AK Alaska 656424 1700139 1/3/1959 49 Juneau Pacific
24 NM New Mexico 121598 314939 1/6/1912 47 Santa Fe Mountain
25 NY New York 54475 141089 7/26/1788 11 Albany Mid-Atlantic
26 CA California 163707 424002 9/9/1850 31 Sacramento Pacific
27 MO Missouri 69709 180546 8/10/1821 24 Jefferson City West North Central
28 OK Oklahoma 69903 181049 11/16/1907 46 Oklahoma City West South Central
29 PA Pennsylvania 46058 119291 12/12/1787 2 Harrisburg Mid-Atlantic
30 SC South Carolina 32007 82898 5/23/1788 8 Columbia South Atlantic
31 WY Wyoming 97818 253349 7/10/1890 44 Cheyenne Mountain
32 SD South Dakota 77122 199745 11/2/1889 40 Pierre West North Central
33 UT Utah 84904 219902 1/4/1896 45 Salt Lake City Mountain
34 AL Alabama 52423 135775 12/14/1819 22 Montgomery East South Central
35 VT Vermont 9615 24903 3/4/1791 14 Montpelier New England
36 AR Arkansas 53182 137742 6/15/1836 25 Little Rock West South Central
37 WA Washington 71303 184674 11/11/1889 42 Olympia Pacific
38 AZ Arizona 114006 295276 2/14/1912 48 Phoenix Mountain
39 WV West Virginia 24231 62759 6/20/1863 35 Charleston South Atlantic
40 LA Louisiana 51844 134275 4/30/1812 18 Baton Rouge West South Central
41 MA Massachusetts 10555 27337 2/6/1788 6 Boston New England
42 FL Florida 65758 170313 3/3/1845 27 Tallahassee South Atlantic
43 GA Georgia 59441 153953 1/2/1788 4 Atlanta South Atlantic
44 HI Hawaii 10932 28313 8/21/1959 50 Honolulu Pacific
45 MD Maryland 12407 32135 4/28/1788 7 Annapolis South Atlantic
46 CO Colorado 104100 269620 8/1/1876 38 Denver Mountain
47 MI Michigan 98810 250738 1/26/1837 26 Lansing East North Central
48 MN Minnesota 86943 225182 5/11/1858 32 Saint Paul West North Central
49 CT Connecticut 5544 14358 1/9/1788 5 Hartford Mid-Atlantic
50 NV Nevada 110567 286368 10/31/1864 36 Frankfort Mountain
=========================================================================================================
Do you want to sort the list in alphabetical order (y/n)? United States of America
=========================================================================================================
Area Admission to Union
# Abbrv State Name SqrMls Km2 Date Order Capital Region
---------------------------------------------------------------------------------------------------------
1 AL Alabama 52423 135775 12/14/1819 22 Montgomery East South Central
2 AK Alaska 656424 1700139 1/3/1959 49 Juneau Pacific
3 AZ Arizona 114006 295276 2/14/1912 48 Phoenix Mountain
4 AR Arkansas 53182 137742 6/15/1836 25 Little Rock West South Central
5 CA California 163707 424002 9/9/1850 31 Sacramento Pacific
6 CO Colorado 104100 269620 8/1/1876 38 Denver Mountain
7 CT Connecticut 5544 14358 1/9/1788 5 Hartford Mid-Atlantic
8 DE Delaware 2489 6447 12/7/1787 1 Dover South Atlantic
9 FL Florida 65758 170313 3/3/1845 27 Tallahassee South Atlantic
10 GA Georgia 59441 153953 1/2/1788 4 Atlanta South Atlantic
11 HI Hawaii 10932 28313 8/21/1959 50 Honolulu Pacific
12 ID Idaho 83574 216456 7/3/1890 43 Boise Mountain
13 IL Illinois 57918 150007 12/3/1818 21 Springfield East North Central
14 IN Indiana 36420 94328 12/11/1816 19 Indianapolis East North Central
15 IA Iowa 56276 145754 12/28/1846 29 Des Moines West North Central
16 KS Kansas 82282 213110 1/29/1861 34 Topeka West North Central
17 KY Kentucky 40411 104665 6/1/1792 15 Frankfort New England
18 LA Louisiana 51844 134275 4/30/1812 18 Baton Rouge West South Central
19 ME Maine 35387 91653 3/15/1820 23 Augusta New England
20 MD Maryland 12407 32135 4/28/1788 7 Annapolis South Atlantic
21 MA Massachusetts 10555 27337 2/6/1788 6 Boston New England
22 MI Michigan 98810 250738 1/26/1837 26 Lansing East North Central
23 MN Minnesota 86943 225182 5/11/1858 32 Saint Paul West North Central
24 MS Mississippi 48434 125443 12/10/1817 20 Jackson East South Central
25 MO Missouri 69709 180546 8/10/1821 24 Jefferson City West North Central
26 MT Montana 147046 380850 11/8/1889 41 Helena Mountain
27 NE Nebraska 77358 200358 3/1/1867 37 Lincoln West North Central
28 NV Nevada 110567 286368 10/31/1864 36 Frankfort Mountain
29 NH New Hampshire 9351 24219 6/21/1788 9 Concord New England
30 NJ New Jersey 8722 22590 12/18/1787 3 Trenton Mid-Atlantic
31 NM New Mexico 121598 314939 1/6/1912 47 Santa Fe Mountain
32 NY New York 54475 141089 7/26/1788 11 Albany Mid-Atlantic
33 NC North Carolina 53821 139397 11/21/1789 12 Raleigh South Atlantic
34 ND North Dakota 70704 183123 11/2/1889 39 Bismarck West North Central
35 OH Ohio 44828 116103 3/1/1803 17 Columbus East North Central
36 OK Oklahoma 69903 181049 11/16/1907 46 Oklahoma City West South Central
37 OR Oregon 98386 254819 2/14/1859 33 Salem Pacific
38 PA Pennsylvania 46058 119291 12/12/1787 2 Harrisburg Mid-Atlantic
39 RI Rhode Island 1545 4002 5/29/1790 13 Providence New England
40 SC South Carolina 32007 82898 5/23/1788 8 Columbia South Atlantic
41 SD South Dakota 77122 199745 11/2/1889 40 Pierre West North Central
42 TN Tennessee 42146 109158 6/1/1796 16 Nashville East South Central
43 TX Texas 268601 695676 12/29/1845 28 Austin West South Central
44 UT Utah 84904 219902 1/4/1896 45 Salt Lake City Mountain
45 VT Vermont 9615 24903 3/4/1791 14 Montpelier New England
46 VT Vermont 9615 24903 3/4/1791 14 Montpelier New England
47 WA Washington 71303 184674 11/11/1889 42 Olympia Pacific
48 WV West Virginia 24231 62759 6/20/1863 35 Charleston South Atlantic
49 WI Wisconsin 65503 169653 5/29/1848 30 Madison East North Central
50 WY Wyoming 97818 253349 7/10/1890 44 Cheyenne Mountain
=========================================================================================================
Press any key to continue . . .The Long Date Format
A date is referred to as long if it includes the names of the month and the day of the week of a date value. This is called the Long Date Format. To get the Long Date of a date, pass a "D" (one d in uppercase) string to the ToString() method of a DateTime object. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2004, 10, 23);
string strDate = date.ToString("D");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Date Portion: {0}\n", strDate);
return 0;
}
}
}
To produce the result, the compiler refers to the Long Date Format combo box of the Customize Regional Options of the Control Panel. The user can change the format by selecting one from the combo box:
Based on the default settings of a computer used in US English, the above program would produce:
Date and Time: 10/23/2004 12:00:00 AM Date Portion: Saturday, October 23, 2004 Press any key to continue . . .
Other Date Formats
The .NET Framework provides other formats, not regularly used but available. To get the name of a month and the year value of a DateTime object, both separated by an empty space, pass a single M (uppercase) as string to the ToString() method of a DateTime object. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2004, 10, 23);
string strDate = date.ToString("M");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Month and Year: {0}\n", strDate);
return 0;
}
}
}
This would produce:
Date and Time: 10/23/2004 12:00:00 AM Month and Year: October 23 Press any key to continue . . .
To include a comma in the result, pass a single y (lowercase) as string to the ToString() method of a DateTime object. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(2004, 10, 23);
string strDate = date.ToString("y");
Console.WriteLine("Date and Time: {0}", date);
Console.WriteLine("Month and Year: {0}\n", strDate);
return 0;
}
}
}
This would produce:
Date and Time: 10/23/2004 12:00:00 AM Month and Year: October, 2004 Press any key to continue . . .
Operations on Dates
The Leap Year
One of the operations performed on date values is to find out whether the year value of a date is a leap year. Fortunately, the static IsLeapYear() method of the DateTime structure can be used to perform this operation. The syntax of this function is:
public static bool IsLeapYear(int year);
This method takes an integer argument and examines it. If the argument, which must be a valid year number, is a leap year, the method returns true; otherwise, it would return false. Here are two examples:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime date = new DateTime(1988, 10, 6);
Console.WriteLine("{0} was a leap year: {1}",
date.Year, DateTime.IsLeapYear(date.Year));
date = new DateTime(1990, 8, 12);
Console.WriteLine("{0} was a leap year: {1}",
date.Year, DateTime.IsLeapYear(date.Year));
return 0;
}
}
}
This would produce:
1988 was a leap year: True 1990 was a leap year: False Press any key to continue . . .
A Time Span
Dates are some of the most important values of the operating system and many applications need them to perform their routine operations. Common operations include adding days to a date, subtracting months from a date, adding years, comparing dates to find out whether one occurs before another, finding out if a payroll falls on a holiday, etc. To perform some of these operations, a unit called an interval is considered as part of a date. A date interval is the number of days, months, or years that have elapsed, or would elapse, from one starting date to another ending date. Once you have specified this interval, you can then apply it to a date with the operation of your choice.
To support the ability to perform operations on dates, the .NET Framework is provides the TimeSpan structure. This structure is equipped with various members that would be applied on the TimeSpan structure. The value produced by this structure is then applied to a DateTime object. To create a date interval, declare a TimeSpan variable and initialize it with the desired value(s). To make this possible, the TimeSpan structure is equipped with various constructors.
Adding and/or Subtracting Days
With the DateTime structure, you can add some days to an existing date or subtract some days from a date value. To support this, the DateTime structure is equipped with the AddDays() method. Its syntax is:
public DateTime AddDays(int days);
Here is an example of calling this method:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime startDate = new DateTime(1988, 10, 6);
Console.WriteLine("Starting Date: {0}", startDate);
// This will be used to add 8 days to the previous date
DateTime endDate = startDate.AddDays(8);
// And display it
Console.WriteLine("Ending Date: {0}\n", endDate);
return 0;
}
}
}
This would produce:
Starting Date: 10/6/1988 12:00:00 AM Ending Date: 10/14/1988 12:00:00 AM Press any key to continue . . .
If you pass a positive value to the DateTime.AddDays() method, a number of days is added to the DateTime variable. If you want to subtract some days from a date, pass the argument with a negative value. This method is able to figure out the year before, the month before, the day before, the day after, the month after, and the year after the designated date.
One of the constructors of the TimeSpan structure takes four arguments. Its syntax
public TimeSpan(int days, int hours, int minutes, int seconds);
The first argument of this constructor represents the number of days. If you are planning to add a number of days to a date, pass a positive integer as the first argument. If you want to subtract a date, pass a negative value. If you want to add only a number of days, pass only this argument.
After creating a TimeSpan object, you can call the Add() method of the DateTime structure to a date value. This would produce a new DateTime object that is the resulting value. Here are examples:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime startDate = new DateTime(1988, 10, 6);
Console.WriteLine("Starting Date: {0}\n", startDate);
// This will be used to add 172 days to the previous date
TimeSpan ts = new TimeSpan(172, 0, 0, 0);
// Pass the TimeSpan object to the date
DateTime endDate = startDate.Add(ts);
// And display it
Console.WriteLine("Ending Date: {0}\n", endDate);
// Subtract 10 days to the previous date
ts = new TimeSpan(-10, 0, 0, 0);
// Pass the TimeSpan object to the date
endDate = startDate.Add(ts);
// And display it
Console.WriteLine("Ending Date: {0}\n", endDate);
return 0;
}
}
}
This would produce:
Starting Date: 10/6/1988 12:00:00 AM Ending Date: 3/27/1989 12:00:00 AM Ending Date: 9/26/1988 12:00:00 AM Press any key to continue . . .
Notice that, when adding or subtracting days, the complier can figure out the previous day, the previous month, the previous year, the following day, the following month, or the following year.
Adding or Subtracting Months to a Date
To add a number of months to a date, the DateTime class is equipped with a method named AddMonths(). Its syntax is:
public DateTime AddMonths(int months);
This method takes one argument as the number of months to be added or subtracted. If you pass the argument with a positive value, the months are added to the date. If you pass a negative value, the number of months is subtracted from the date.
Adding or Subtracting Years to a Date
To get the date a few years before or after a known date, you can add years to, or subtract years from, a known date. To support this operation, the DateTime class provides a method named AddYears(). Its syntax is:
public DateTime AddYears(int years);
The argument passed to the method is the number of years. A positive value (or a negative value) adds (or subtracts) the number of years to (or from) the date.
Logical Operations on Dates
Using the logical operators we reviewed for primitive types, you can compare the values of dates for equality, differences, lower or greater values. To support these operations, the DateTime structure have the logical operators configured.
To compare two dates, apply the desired Boolean operator the same day you would two variables of primitive types. Here is an example:
using System;
namespace DateAndTime
{
class Program
{
static int Main()
{
DateTime startDate = new DateTime(1988, 10, 6);
Console.WriteLine("Starting Date: {0}", startDate);
// This will be used to add 8 days to the previous date
DateTime endDate = startDate.AddDays(8);
// And display it
Console.WriteLine("Ending Date: {0}\n", endDate);
if (startDate < endDate)
Console.WriteLine("{0} Occurs Before {1}", startDate, endDate);
return 0;
}
}
}
This would produce:
Starting Date: 10/6/1988 12:00:00 AM Ending Date: 10/14/1988 12:00:00 AM 10/6/1988 12:00:00 AM Occurs Before 10/14/1988 12:00:00 AM Press any key to continue . . .
Practical Learning: Ending the Lesson
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