What you meant by function call function definition and the function declaration in c and c plus plus?

Answer 1

A function call is a function that is called from within another function.

Functions must be declared before they can be called, in order to establish the function's prototype (signature) so the compiler knows which function to call.

The function definition contains the implementation of the function and may be specified in the declaration itself (inline), or it can be defined in another file altogether.

Declarations are typically placed in a header file so that they may be included (#include) in any files that require them, including the file containing the definition of the function declared in the header file. Including a file is the same as typing the file contents in full at the point of inclusion, thus ensure the declarations are available to the compiler before they are used.

The following example shows a forward declaration of a function that is defined later.

// forward declaration.

int square(int);

// the main function (the entry point of application).

int main()

{

// a function call.

int s = square( 5 );

// returns the value 25 to the calling process (e.g., the operating system).

return( s ); }

// definition of the function declared earlier.

int square(int data)

{

// returns the square of the data to the calling function, e.g., main().

return( data * data );

}

Function is a self contained block or a sub program of one or more statements that performs a special task when called.