Borland C++ Builder allows you to create various types of applications. In this book, we will use only C++ to create console applications. A console application is one that displays its result in a DOS window. The user interacts with it by using the keyboard with very little involvement with the mouse.

1. On the main menu of Bcb, click File -> New… If you are using Borland C++ Builder 6, click File -> New -> Other…
    
   
2. On the New Items dialog box, click Console Wizard
3. Click OK. 
4. In the Console Wizard dialog, click the C++ radio button and make sure that only the Console Application check box is checked (for this application):
    
   
5. Click OK.
6. If you receive a message box asking you to save changes made to a project, click No.
7. After a few seconds, a skeleton file is ready for you.
   In order to make sure we start from scratch, delete everything in that file and make it empty.
8. From what we learned earlier, in the empty file, type:
   
   #include <iostream.h>
9. To include more than one file, you can write one under the other. For example, to include the conio.h file, change the file as follows:
   
   #include <iostream.h>
   #include <conio.h> 
   

Computer programming is the art of telling the computer what to do, when to do it, and how to do it. The programmer accomplishes this by giving instructions to the computer. An example of an instruction is, "Get a number from the user", or “Display a picture on the screen". The computer carries a lot of such assignments. In C++, an assignment is called a function; it is a task you ask the computer to perform to successfully render an intended result. Like any of the objects you will be using in your programs, a function has a name. The name of a function is a letter or a combination of letters and digits. To differentiate the name of a function from other objects, the name of a function is followed by parentheses. As an assignment, a function is made of a set of instructions. These instructions are listed in a group of lines called the body of the function. The body of a function starts with an opening curly bracket "{" and ends with a closing curly bracket "}"; everything in between is part of the function. Therefore, to use a function in your program, its syntax is:

FunctionName() {}

Actually, a function is a little more than that, but for now, this is enough for us.

The most used function in C++ is called main. The main() function can take various forms, the easiest version is as follows:

main() {}

A C++ file is made of statements. These are sequences of actions you ask C++ to perform while the program is running. You can write such a statement on one line, or you can span more than one line. By default, when you start a new line, C++ believes that you are starting a new statement. To let C++ know when a statement ends, you write a semi-colon at the end of the line. For example, to write one statement, you could use:

Here-Is-A-C++-Statement;

To span more than one line, type a semi-colon only when the statement is over. Here is an example:

A-Long-Statement-From-C++-That-Spans-
More-Than-One-Line;

1. From what we have learned so far, change the contents of your file as follows:
   
   #include <iostream.h>
   #include <conio.h>
   main(){}
2. You can include one function inside of another. As an example, change the main() function as follows:
   
   main(){getch();}

A program would not mean much unless it accomplishes the desired purpose. To examine how your development is proceeding, as a beginning programmer, you should regularly ask C++ to show you the result.

The (small) program we have written is really plain English, something we can read and analyze. Unfortunately, the computer does not understand what it means; this is because the computer "speaks" its own language called the Machine Language. For the computer to understand what your program means, you need an intermediary program that can translate your English to machine language and vice versa. This program is called a compiler, and it is supplied to you. The process of executing a program is done in various steps that Borland C++ Builder can resume as one.

There are three ways you can execute a program in Borland C++ Builder. To execute a program, you can press F9, you can also use the main menu where you would click Run ª Run. On the toolbar, you can also click the Run button 

1. On the Debug toolbar, click the Run button .
   As you see, the program does not do much because we did not write a formal assignment
2. To close the DOS window, press Enter on your keyboard.

Although it worked fine, the program we have just used lacks many things. You should make your programs easy to read and navigate. This is accomplished by writing each statement on its own line. For example, the above program can be re-written as follows:

#include <iostream.h>
#include <conio.h>
main()
{
    getch();
}

The iostream.h library contains a special operator used to display something on the screen.

cout is a class and not an operator. For now, we will call it an operator.

This is done with the cout operator (pronounce "see-out"). To use this operator, type it followed by two "less than" signs "<<", the statement you want to display, and end the line with a semi-colon. An example would be:

cout << Line-Of-Statement;

There are mainly two kinds of items you display with a cout operator: expressions or strings. An expression is a character, a symbol, a word or a combination of those, usually from performing an operation or an assignment. There are specific rules we will learn and follow when displaying an expression. A string is a character, a symbol, a word or a group of words that you ask the compiler to display "as is". To display a string, you enclose it between a pair of double-quotes. For example, to display C++ Programming, you would write:

cout << "C++ Programming";

You can also display a long string and span more than one line. In this case, cout would detect the end of the string when it finds a semi colon after the second double-quotes. There are two methods you can follow. To display a long string, after the cout operator and its <<, start the string with double-quotes; include each line in double-quotes; the compiler will append each line to the next. Here is an example:

cout << "In 1873 Mark Twain and Charles Dudley Warner created an enduring "
"label for their times when they collaborated on a novel entitled "
"The Gilded Age. Ref: America A Narrative History.";

To display sections of strings, you can use one cout but each line should start with its own << operator. Here is an example:

cout << "The White House "
<< "Pennsylvania Avenue";

Indentation is another feature that makes your program easy to read. Indentation is a technique of grouping lines of code by category. To effectively use indentation, identify some special symbols in your program. For example, we saw that the body of a function starts with an opening curly bracket “{“ and ends with a closing curly bracket “}”. To delimit the items that are inside of a function, you should indent them by two empty spaces or one tab. When inside of a function, if you press Tab, C++ Builder refers to the indentation amount specified in the Editor Properties. By default, C++ Builder sets a Tab press to 8 characters, which usually seems too much. Most programmers, including me, want a Tab to be equivalent to 4 characters. To change the indentation amount when pressing Tab, open the Editor Properties dialog box (Tools -> Editor Options…) and click the General property sheet. In the Tab Stops combo box, specify the amount you want and click OK:

Using indentation, the program could be written:

#include <iostream.h>
#include <conio.h>
main()
{
    getch();
}

Indentation should be incremental. That is, when a line of code appears to be a child of the previous line, the new line should be indented. The address lines we saw earlier can be written as:

cout << "The White House "
     << "Pennsylvania Avenue";

1. Change the content of the file as follows:
    

   #include <iostream.h> #include <conio.h> main() { getch(); }

2. To use the cout operator, change the main() function as follows:
    

   #include <iostream.h> #include <conio.h> main() { cout << "Press any key to continue..."; getch(); }

3. To execute and test your program, on the main menu, click Run -> Run
4. To close the DOS window, press Enter, and return to Bcb. 

Comments in a C++ file serve as documentation entities that help you and other people to read your program. Comments are lines of text that you can write in plain English because the compiler skips them completely.

There are two styles of comments in C++. To write a comment on one line, start the line with two forward slashes. Here is an example of a comment:

// The compiler doesn’t read this line.

To span a comment on more than one line, you can start each line with //. An alternative is to include the comment section between /* and */. Here is an example:

/* The compiler will ignore this whole section and will jump over it.*/

1. Change the content of the file as follows:
    

   // Introductory lesson to C++ #include <iostream.h> #include <conio.h> /* This is the main function. It is included on every C++ program. It is the central point of a C++ application.*/ main() { cout << "Press any key to continue..."; getch(); } // -------------------------------------------

2. Execute the program to see the result

An escape sequence is a character that holds a special meaning to the compiler such as switching to the next line or adding a tab indentation. Although an escape sequence is a character by definition, it is created using the backslash “\” followed by a specific character. For example, the escape sequence \n asks the compiler to add or create a new line, also referred to as Carriage Return or “Carriage Return – Line Feed”. The new line can also be created with a stand-alone endl. Here is an example:

cout << endl;

To use an escape sequence by itself, you can include between single quotes: ‘\n’ or double quotes: “\n”. Because escape sequences are specially recognized by the compiler, they can be included in a cout string. Since the compiler will still read a string, if it finds an escape sequence, it acts accordingly. Here is a list of escape sequences and their meanings:

 

Practical Learning: Using Escape Sequences

1. To implement examples of using escape sequences, change your program as follows:
    

   // Introductory lesson to C++ #include <iostream.h> #include <conio.h> /* This is the main function. It is included on every C++ program. It is the central point of a C++ application.*/ main() { cout << '\t' << "- Borland C++ Builder -\a" << endl; cout << "This will end our session today" << "\n"; cout << "\n\nPress any key to continue..."; getchar(); }

2. To test the program, press F9
3. After using the program, return to Bcb

A program in Borland C++ Builder is called a project. As an application, it is saved in a few steps. To save a project, on the Standard toolbar, you can click the Save All button.

1. On the Standard toolbar, click Save All
2. Type Main to replace the name of the Unit1
3. Click the arrow of the Save In combo box and click the My Documents
4. Click the Create New Folder button
5. Type Exercise01 and press Enter
6. Double-click Exercise01 to display it in the Save In combo box
7. Click Save
8. Type Exercise to replace the name of the project
9. Click Save