Every C and C++ program must have a program-startup function.

• Console-based programs call the main function at startup.
• Windows GUI programs call the WinMain function at startup.

Where you place the startup function is a matter of preference. Some programmers place main at the beginning of the file, others at the end. Regardless of its location, the following points about main always apply.

• Arguments to main
• Wildcard arguments
• Using -p (Pascal Calling Conventions)
• The value that main() returns