how to swap 2 variables in code example

Example 1: swap using third variable

// SWAP USING THIRD VARIBLE
#include <stdio.h> 
int main()
{
int var1, var2, temp; 
printf("Enter two integersn");
scanf("%d%d", &var1, &var2);
printf("Before SwappingnFirst variable = %dnSecond variable = %dn", var1, var2);
temp = var1;
var1 = var2;
var2 = temp;
printf("After SwappingnFirst variable = %dnSecond variable = %dn", var1, var2);
return 0;
}

Example 2: how to swap 2 numbers without 3rd variable

int a = 3;
int b = 5;
a = b*a;
b = a/b
a = a/b