C Program to Swap Two Numbers using third Variable

Write a c program to swap two numbers using third variable. In this program, we are going write a code to take two input numbers from a user and swap both numbers using third or temp variable.


How to Swap Two Numbers using Third Variable


i) Take an input number from a user. Let's say user has entered two numbers 4 and 5.

     first = 4;
    second = 5;

ii) Declare third variable temp which holds the value.


     Let's assign the value of first in temp.

      temp = first;

     Assign the value of second in first. 

      first = second;

     Assign the value of temp in second.

     second = temp;

Before swapping : a =4  and b = 5
After swapping : a = 5 and b = 4

Swap two numbers without using third variable

C, C++ Interview Questions
     

C Program to Swap Two Numbers using Third Variable

We have discussed the logic to swap two numbers using third variable. Let's write a c code to implement this logic.

#include<stdio.h>

int main()
{
   int first, second, temp;    

   printf("Enter two numbers\n");
   scanf("%d %d", &first, &second);

   printf("\nBefore swapping a = %d and b = %d", first, second);
   
   /* Logic to swap two numbers
      using third variable */

   temp   = first;
   first  = second;
   second = temp;

   printf("\nAfter swapping a = %d and b = %d",first , second);
  
   return 0;
   
}

Output:

Enter two numbers :  4   5

Before swapping a = 4 and b = 5
After swapping a = 5 and b = 4

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