Question

Question 3: What is Function? Explain with examples. Provide at least 2 program examples.

Answer 1

What is function?

Function is a group of statements that performs some operations and returns result. If there is a need to run specific lines of code multiple times for different values than insted of writing same statements multiple times for different values you can declare a function that contains the code and then call that function from your main program for different values. So function basically used to provide reusability into the code.

Example 1:

#include <stdio.h>
// function getMax that calculates the maximum of 2 values
int getMax(int num1, int num2) {

   /* local variable declaration */
   int result;
 
    //checks if num1 > num2 then max is num1        
   if (num1 > num2)
      result = num1;
      
    //checks if num1 < num2 then max is num2  
   else
      result = num2;
 
    //return the result     
   return result; 
}
int main() {

   int max;

   //calls getMax method for 20 and 30
   max = getMax(20,30);
   printf("Max is = %d\n", max );
    
   //calls getMax method for 37 and 21
   max = getMax(37,21);
   printf("Max is = %d\n", max );
}

Output:

Example 2:

#include <stdio.h>
#include <stdbool.h>

// function checknum checks if number is even or odd
bool checknum(int num) {

    /* modulo operator returns the remainder of integer division
    if any number is divisible by 2 then it is an even number otherwise
    it is an odd number
    */
    
    //if num is even then return true else returns false
    if(num % 2 == 0){
        return true;
    }
    
    else{
        return false;
    }
}
int main() {

   bool ans;

   //call checknum function for value 20 and store the result in ans variable        
   ans = checknum(20);
   
   //if ans is true then the number is even and prints number is even
   if(ans){
       printf("Number is even \n");
   }
   
   //if ans is false then the number is odd and prints number is odd
   else{
       printf("Number is odd\n");
   }
   
   //call checknum function for value 3 and store the result in ans variable
   ans = checknum(3);
   
   //if ans is true then the number is even and prints number is even
   if(ans){
       printf("Number is even\n");
   }
   
   //if ans is false then the number is odd and prints number is odd
   else{
       printf("Number is odd\n");
   }
   
  
}

Output: