How will you swap two variables? Write different approaches for the same.

Embedded C - Interview Questions

Using Extra Memory Space :

int num1=20, num2=30, temp;
temp = num1;
num1 = num2;
num2 = temp;

Using Arithmetic Operators :

int num1=20, num2=30;
num1=num1 + num2;
num2=num1 - num2;
num1=num1 - num2;

Using Bit-Wise Operators :

int num1=20, num2=30;
num1=num1 ^ num2;
num2=num2 ^ num1;
num1=num1 ^ num2;

Using One-liner Bit-wise Operators :

int num1=20, num2=30;
num1^=num2^=num1^=num2;

The order of evaluation here is right to left.

Using One-liner Arithmetic Operators :

int num1=20, num2=30;
num1 = (num1+num2)-(num2=num1);

Here the order of evaluation is from left to right.