void main(void)
{
int a=15,b=24;
printf("a=%d b=%d",a,b);
a=a^b;
b=b^a;
a=a^b;
printf("a=%d b=%d",a,b);
}

a=15 0000 1111 ^

b=24 0001 1000

0001 0111 =23

0000 1111 =15

0001 1000 =24