Why do these swap functions behave differently?

Question

#include 

void swap1(int a, int b)
{
    int temp = a;

    a = b;
    b = temp;
}

void swap2(int *a, int *b)
{
    int *temp = a;

    a = b;
    b         


        

Answer 1

Just for fun, exchange values without the use of a temporary variable

x = x ^ y
y = x ^ y
x = x ^ y