Swap two numbers in-place ==> without using a temp variable

swap.java

//This method works only with integers
int a = 5;
int b = 7;

a = a-b; //diff. a = -2
b = a+b; // b = 5
a = b-a; // a = 7

//This method relies on bit manipulation and does not depend on the number format
int c = 3;
int d = 4;

c = c^d;
d = c^d;
c = c^d;