A Review of BuiltIn Functions 

Constants, Expressions and Formulas 
Introduction to Constants 
A constant is a value that does not change. It can be a number, a string, or an expression. To create a constant, use the Const keyword and assign the desired value to it. Here is an example: Private Sub CreateConstant() Const Number6 = 6 End Sub 
After creating the constant, you can use its name wherever its value would have been used. Some of the constants you will use in your expressions have already been created. We will mention them when necessary.
An expression is one or more symbols combined with one or more values to create another value. For example, +16 is an expression that creates the positive value 16. Most expressions that we know are made of arithmetic calculations. An example is 422.82 * 15.55. 
To add an expression to a selected cell, assign it to the ActiveCell object. Here is an example: Sub Exercise() ActiveCell = 422.82 * 15.5 End Sub
A formula is another name for an expression. It combines one or more values, one or more variables, to an operator, to produce a new value. This also means that you use the same approach or building an expression when creating a formula. To assist you with assigning the result of a formula to a cell or a group of cells, the Range class is equipped with a property named Formula. This property is of type Variant, which means its value can be anything, not necessarily a number. After accessing the Formula property, you can assign whatever value, expression, or formula you want to it. Here are examples: Sub Exercise() Rem Using the Formula property to assign a string to the active cell ActiveCell.Formula = "Weekly Salary:" Rem Using the Formula property to assign an expression to cell B2 Range("B2").Formula = 24.5 * 42.5 Rem Using the Formula property to assign Rem the same string to a group of cells Range("C2:F5, B8:D12").Formula = "Antoinette" End Sub If you are creating a worksheet that would be used on computers of different languages, use FormulaLocal instead. The FormulaLocal property is equipped to adapt to a different languagebased version of Microsoft Excel when necessary. Besides Formula, the Range class is also equipped with a property named FormulaR1C1. Its functionality is primarily the same as Formula. Here are examples: Sub Exercise() Rem Using the Formula property to assign a string to the active cell ActiveCell.FormulaR1C1 = "Weekly Salary:" Rem Using the Formula property to assign an expression to cell B2 Range("B2").FormulaR1C1 = 24.5 * 42.5 Rem Using the Formula property to assign Rem the same string to a group of cells Range("C2:F5, B8:D12").FormulaR1C1 = "Antoinette" End Sub If you are creating the worksheet for various languages, use FormulaR1C1Local instead.
We know how to create and use functions. Instead of creating your own function, you can use one of those that ship with the VBA language. This language provides a very extensive library of functions so that, before creating your own, check whether the function exists already. If so, use it instead. In later sections and lessons, we will review most of the builtin functions of VBA. To use a VBA builtin function, simply use as you would an expression. That is, assign its returned value to a cell. Here is an example: Sub Exercise() Range("B2:B2") = Len("Paul Bertrand Yamaguchi") End Sub
To assist you with developing smart worksheets, Microsoft Excel enjoys one of the largest libraries of functions you will ever see in a system. To see a list of the available functions, on the Ribbon, you can click Formulas: The functions are listed by category. To see the list of functions in a category, you can click the Financial, the Logical, the Text, the Date & Time, the Lookup & Reference, or the Math & Trig button. When you click, a list would appear. Here is an example: After clicking one of those buttons, you can see the function you want to use. If the function does not appear, you can click the More Functions button. This buttons holds four other categories of functions. After clicking the button, it displays a menu. You can position the mouse on one to view its list: While the buttons show the functions in their respective categories, you can see all of the functions in one list. In fact, another way to look for a function is by using the Insert Function dialog box. To access it, in the Function Library section of the Ribbon:
This would display the Insert Function dialog box:
The functions are organized in categories in the middle combo box of the Insert Function dialog box. Because there are so many functions, we will cannot possibly review all of them. When necessary, we will use those we need. To use a Microsoft Excel builtin function in your code, include the assignment operator followed by the function's whole expression in doublequotes. Here is an example: Sub Exercise() Range("B5:B5") = "=SomeFunction(B2, B3, B4)" End Sub
You may recall that when studying data types, we saw that each had a corresponding function used to convert a string value or an expression to that type. As a reminder, the general syntax of the conversion functions is: ReturnType = FunctionName(Expression) The Expression could be of any kind. For example, it
could be a string or expression that would produce a value such as the result of a calculation. The conversion function would take such a value, string, or
expression and attempt to convert it. If the conversion is successful,
the function would return a new value that is of the type specified by
the ReturnType in our syntax.
These functions allow you to convert a known value to a another type.
In the previous lesson, we had an introduction to builtin functions but we mostly reviewed only stringbased functions. Both Microsoft Excel and the Visual Basic language provide each an extensive library of functions. We refer to some functions as accessories because you almost cannot anything about them or at least they are very useful. To assist you with specifying the color of anything, the VBA is equipped with a function named RGB. Its syntax is: Function RGB(RedValue As Byte, GreenValue As Byte, BlueValue As Byte) As long This function takes three arguments and each must hold a value between 0 and 255. The first argument represents the ratio of red of the color. The second argument represents the green ratio of the color. The last argument represents the blue of the color. After the function has been called, it produces a number whose maximum value can be 255 * 255 * 255 = 16,581,375, which represents a color.
The Microsoft Excel's SUM function is used to add the numeric values of various cells. The result can be displayed in another cell or used in an expression. Like all functions of the Microsoft Excel library, you can use SUM visually or programmatically. To use the SUM() function visually, on the Ribbon, in the Home tab, the Editing section is equipped with a button called the AutoSum
The absolute value of a number x is x if the number is (already) positive. If the number is negative, then its absolute value is its positive equivalent. For example, the absolute value of 12 is 12, while the absolute value of –12 is 12. To get the absolute value of a number, you can use either the Microsoft Excel's ABS() or the VBA's Abs() function. Their syntaxes are: Function ABS(number) As Number Function Abs(number) As Number This function takes one argument. The argument must be a number or an expression convertible to a number:
If you have a decimal number but are interested only in the integral part, to assist you with retrieving that part, the Visual Basic language provides the Int() and the Fix() functions. In the same way, the Microsoft Excel library provides the INT() function to perform a similar operation. Their syntaxes are: Function Int(ByVal Number As { Number  Expression } ) As Integer Function Fix(ByVal Number As { Number  Expression } ) As Integer Function ABS(ByVal Number As { Number  Expression } ) As Integer Each function must take one argument. The value of the argument must be numberbased. This means it can be an integer or a floatingpoint number. If the value of the argument is integerbased, the function returns the (whole) number. Here is an example Sub Exercise() Dim Number As Integer Number = 28635 ActiveCell = MsgBox(Int(Number), vbOKOnly, "Exercise") End Sub This would produce: If the value of the argument is a decimal number, the function returns only the integral part. Here is an example Sub Exercise() Dim Number As Double Number = 7942.225 * 202.46 ActiveCell = MsgBox(Int(Number), vbOKOnly, "Exercise") End Sub This would produce: This function always returns the integral part only, even if you ask it to return a floatingpointbased value. Here is an example: Sub Exercise() Dim Number As Single Number = 286345.9924 ActiveCell = MsgBox(Int(Number), vbOKOnly, "Exercise") End Sub This would produce:
When it receive values for its cells, by default, Microsoft Excel displays text left aligned and numbers right aligned. In some situations, you will want to treat numbers as text. Although Microsoft Excel displays all numbers right aligned, as a smart financial and business application, it can distinguish between different types of numbers. It can recognize a date, a currency, or a percentage values, but the computer wants you to specify the way numbers should be displayed, giving you the ability to decide what a particular number represents, not because the software cannot recognize a number, but because a value can represent different things to different people in different scenarios. For example 1.5 might represent a half teaspoon in one spreadsheet while the same 1.5 would represent somebody's age, another spreadsheet's percentage, or etc.
When it comes to displaying items, Microsoft Excel uses various default configurations. The computer's Regional Options or Regional Settings govern how dates, numbers, and time, etc get displayed on your computer. Microsoft Excel recognizes numbers in various formats: accounting, scientific, fractions, and currency. As the software product can recognize a number, you still have the ability to display the number with a format that suits a particular scenario. To visually control how a cell should display its number, on the Ribbon, click Home and use the Number section. To assist you with programmatically specifying how a cell should display its number, the Range class is equipped with a property named Style. To further assist with number formatting, the Visual Basic language provides a function named Format. This function can be used for different types of values The most basic technique consists of passing it an expression that holds the value to display. The syntax of this function is: Function Format(ByVal Expression As Variant, _ Optional ByVal Style As String = "" _ ) As String The first argument is the value that must be formatted. Here is an example: Sub Exercise() Dim Number As Double Number = 20502.48 ActiveCell = Format(Number) End Sub The second argument is optionally. It specifies the type of format you want to apply. We will see various examples.
To visually specify that you want a cell to display its numeric value with the comma delimiter, click the cell to give it focus. Then, in the Home tab of the Ribbon, in the Number section, click the Comma Style button . The thousand numbers would display with a comma sign which makes it easier to read. To visually control the number of decimal values on the right side of the comma, in the Number section of the Ribbon:
To programmatically specify that you want a cell to display the comma style of number, assign the "Comma" string to the Style property of the Range class. Here is an example: Sub SpecifyComma() ActiveCell.Style = "Comma" End Sub Alternatively, to programmatically control how the number should display, you can pass the second argument to the Format() function. To produce the number in a general format, you can pass the second argument as "g", "G", "f", or "F" . To display the number with a decimal separator, pass the second argument as "n", "N", or "Standard". Here is an example: Sub Exercise() Dim Number As Double Number = 20502.48 ActiveCell = Format(Number, "STANDARD") End Sub An alternative to get this format is to call a function named FormatNumber. Its syntax is: Function FormatNumber( ByVal Expression As Variant, Optional ByVal NumDigitsAfterDecimal As Integer = 1, Optional ByVal IncludeLeadingDigit As Integer, Optional ByVal UseParensForNegativeNumbers As Integer, Optional ByVal GroupDigits As Integer ) As String Only the first argument is required and it represents the value to display. If you pass only this argument, you get the same format as the Format() function called with the Standard option. Here is an example: Sub Exercise() Dim Number As Double Number = 20502.48 ActiveCell = FormatNumber(Number) End Sub This would produce the same result as above. If you call the Format() function with the Standard option, it would consider only the number of digits on the right side of the decimal separator. If you want to display more digits than the number actually has, call the FormatNumber() function and pass a second argument with the desired number. Here is an example: Sub Exercise() Dim Number As Double Number = 20502.48 ActiveCell = FormatNumber(Number, 4) End Sub In the same way, if you want the number to display with less numbers on the right side of the decimal separator, specify that number. We saw that you could click the Decrease Decimal button on the Ribbon to visually control the number of decimal values on the right side of the comma and you could continuously click that button to decrease the number of digits. Of course, you can also exercise this control programmatically. You can call the Format() function to format the number with many more options. To represent the integral part of a number, you use the # sign. To specify the number of digits to display on the right side of the decimal separator, type a period on the right side of # followed by the number of 0s representing each decimal place. Here is an example: Sub Exercise() Dim Number As Double Number = 20502.48 ActiveCell = Format(Number, "#.00000") End Sub The five 0s on the right side of the period indicate that you want to display 5 digits on the right side of the period. You can enter as many # signs as you want; it would not change anything. Here is an example: Sub Exercise() Dim Number As Double Number = 20502.48 ActiveCell = Format(Number, "##########.00000") End Sub This would produce the same result as above. To specify that you want to display the decimal separator, include its character between the # signs. Here is an example: Sub Exercise() Dim Number As Double Number = 20502.48 ActiveCell = Format(Number, "###,#######.00000") End Sub You can include any other character or symbol you want in the string to be part of the result, but you should include such a character only at the beginning or the end of the string, otherwise the interpreter might give you an unexpected result.
Another regular type of number used in applications and finances is the currency. A currency value uses a special character specified in the Control Panel. In US English, this character would be the $ sign: To visually that a cell should display its number as currency, in the Number section of the Ribbon, click the Currency Style button . To programmatically specify that you want a cell to display its value with the currency style, assign the "Currency" string to the Style property of the Range class. Here is an example: Sub SpecifyComma() ActiveCell.Style = "Currency" End Sub Alternatively, to programmatically display the currency symbol in the result of a cell or a text box of a form, you can simply add it as part of the second argument to the Format() function. Here is an example: Sub Exercise() Dim Number As Double Number = 205.5 ActiveCell = Format(Number, "$###,#######.00") End Sub Fortunately, there are more professional options. Besides the Format() function, to support currency formatting of a number, the Visual Basic language provides the FormatCurrency() function. Its syntax is: Function FormatCurrency( ByVal Expression As Variant, Optional ByVal NumDigitsAfterDecimal As Integer = 1, Optional ByVal IncludeLeadingDigit As Integer = 2, Optional ByVal UseParensForNegativeNumbers As Integer = 2, Optional ByVal GroupDigits As Integer = 2 ) As String Only the first argument is required. It is the value that needs to be formatted. Here is an example: Sub Exercise() Dim UnitPrice As Double UnitPrice = 1450.5 ActiveCell = FormatCurrency(UnitPrice) End Sub Notice that, by default, the FormatCurrency() function is equipped to display the currency symbol (which, in US English is, the $ sign), the decimal separator (which in US English is the comma), and two decimal digits. If you want to control how many decimal digits are given to the result, pass a second argument as an integer. Here is an example: Sub Exercise() Dim UnitPrice As Double UnitPrice = 1450.5 ActiveCell = FormatCurrency(UnitPrice, 4) End Sub Instead of calling the FormatCurrency() function to format a number to currency, you can use the Format() function. If you do, pass it a second argument as "Currency", "c", or "C". Here is an example: Sub Exercise() Dim CarPrice As Double CarPrice = 42790 ActiveCell = Format(CarPrice, "Currency") End Sub
A percentage of a number represents its rate on a scale, usually of 100 (or more). The number is expressed using digits accompanied by the % sign. To visually specify that a number in a cell should be treated a percentage value, in the Number section of the Ribbon, click the Percent Style button . To programmatically use a percentage number in a cell or the control of a form, you can use the Format() function. Besides the Format() function, to support percent values, the Visual Basic language provides a function named FormatPercent. Its syntax is: Function FormatPercent( ByVal Expression As Variant, Optional ByVal NumDigitsAfterDecimal As Integer = 1, Optional ByVal IncludeLeadingDigit As Integer = 2, Optional ByVal UseParensForNegativeNumbers As Integer = 2, Optional ByVal GroupDigits As Integer = 2 ) As String Only the first argument is required and it is the number that needs to be formatted. When calling this function, pay attention to the number you provide as argument. If the number represents a percentage value as a fraction of 0 to 1, make sure you provide it as such. An example would be 0.25. In this case, the Visual Basic interpreter would multiply the value by 100 to give the result. Here is an example: Sub Exercise() Dim DiscountRate As Double DiscountRate = 0.25 ActiveCell = FormatPercent(DiscountRate) End Sub If you pass the value in the hundreds, the interpreter would still multiply it by 100. Although it is not impossible to get a percentage value in the hundreds or thousands, you should make sure that's the type of value you mean to get. Besides the FormatPercent() function, to format a number to its percentage equivalent, you can call the Format() function and pass the second argument as "Percent", "p", or "P". Here is an example: Sub Exercise() Dim DiscountRate As Double DiscountRate = 0.25 ActiveCell = MsgBox("Discount Rate: " & _ Format(DiscountRate, "Percent"), _ vbOKOnly, "Exercise") End Sub
Although you can do most of cells configurations using the Ribbon, Microsoft Excel provides the Format Cells dialog box. This dialog box presents more options and more precision. To display the Format Cells dialog box:



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