Functions

A function is a group of statements that helps in performing the task. If you have noticed in previous programs there is at least one function in every C program i.e. main()

To make your code more efficient you can divide up your code into different functions. A function declaration informs the compiler about the function's name, return type, and parameters. The function definition contains the actual body of the function.

 

The general syntax of function definition in C language is as follows-

 

return_type function_name( parameter list ) {

   body of the function

}

 

Let's know in brief about this syntax.

  • Function Name- It contains the name of the function and the parameter list together.

  • Return Type- We have used the return type in the above syntax. It is just a data type that returns the value of function returns. Some functions do not have to return a value.

  • Parameters- Parameters are simply like a placeholder. This value is referred to as the actual parameter.

  • Function Body- In the body of a function there is a collection of statements that define what the function does.

 

 

Example of Functions in C language

Program:

#include <stdio.h>

 

/* Declare a function */

int max(int num1, int num2);

 

int main () {

 

   /* To define a local variable */

   int a = 200;

   int b = 320;

   int ret;

 

   /* TO Call a function and get maximum value */

   ret = max(a, b);

 

   printf( "The Maximum value is : %d\n", ret );

 

   return 0;

}

 

/* The function returning the maximum between two numbers */

int max(int num1, int num2) {

 

   /* To Declare a local variable */

   int result;

 

   if (num1 > num2)

      result = num1;

   else

      result = num2;

 

   return result; 

}

 

Output:

The Maximum value is : 320