public class PassByCopy
{
    public static void main(String[] args) 
    {
        int x;
        
        x = 4;
        System.out.println(x);

        increment( x ); // Pass x by copying, 
                        // Just like: a = x

        System.out.println(x); // x UNCHANGED
    } 
    
    public static void increment(int a ) // a and x are different variables
    {
        a = a + 1;
    }  
}