Program in C plus plus to swap two numbers with out a third variable

Give two numbers of we want to swap them, the commonly used method is to swap them using a third variable as shown below.

temp = value 1 // Assign the value1 to a temporary variable value1 = value2 // Assign the value2 to value1. As value1 is saved we can overwrite it without any problem of losing it. value2 = temp //Now assign the value of temp, which has value1 stored in it to value2.
But the use of third variable is not really needed and some times not recommended as it leads to unnecessary memory usage. We can swap the two numbers using the bitwise XOR operation too as shown below.

value1 = value2(bitwise XOR) value1 value2 = value2(bitwise XOR) value1 value1 = value2(bitwise XOR) value1

Example:

If value1 = 5 and value2 = 6 value1 = 5 (bitwise XOR) 6 = 3 value2 = 6 (bitwise XOR) 3 = 5 value1 = 5 (bitwise XOR) 3 = 6

The same program implemented in c plus plus below. The compilation and output are shown as run in Linux terminal using g++ compiler.

/*Program to swap two numbers with out using third variable*/ #include<iostream> using namespace std ; int main() { int a=5,b=6; cout << "The numbers before swapping are \n" ; cout << "a ="<<a<<",b="<<b << "\n\n"; a=a^b; cout << "The numbers a and b after first xor operation are \n" ; cout << "a ="<<a<<",b="<<b << "\n\n"; b=a^b; cout << "The numbers a and b after second xor operation are \n" ; cout << "a ="<<a<<",b="<<b << "\n\n"; a=a^b; cout << "The numbers after swapping are \n" ; cout << "a ="<<a<<",b="<<b << "\n\n"; } save the above program as swap_with_out_temp.cpp Compile and Execute : g++ swap_with_out_temp.cpp -o swap_with_out_temp ./swap_with_out_temp

Output: The numbers before swapping are a =5,b=6 The numbers a and b after first xor operation are a =3,b=6 The numbers a and b after second xor operation are a =3,b=5 The numbers after swapping are a =6,b=5