C++ Functions Tutorial

C++ Functions Tutorial

C++ Functions

We know that function play an important role in C program development. Dividing a program into functions is one of the major principles of top-down, structure programming.

Another advantage of using functions is that it is possible to reduce the size of a program by calling and using them at different places in the program

Example

	void show ( );	/* Function declaration */

	main ( )

	{

		………..

		Show ( );	/* Function call */ 

		………..

	}


	void show ( )	/* Function definition */

	{

		………..	/* Function body */

		………..	

		………..

	}

THE MAIN FUNCTION

C does not specify any return type for the main() function which is the starting point for the execution of a program. The definition of main() would look like this:

main ( )
{
	// main program statements
}

This is perfectly valid because the main () in C does not return any value.

In C++, the main() returns a value of type int to the operating system. C++, therefore, explicitly defines main() as matching one of the following prototypes:

int main();
int main(int args, char * argv []);