Tag: long-integer

Why are the implementations of the static method compare for Long, Integer and Short in Java’s library different?

For Long:

public static int compare(long x, long y) {
    return (x < y) ? -1 : ((x == y) ? 0 : 1);
}

For Integer:

public static int compare(int x, int y) {
    return (x < y) ? -1 : ((x == y) ? 0 : 1);
}

For Short:

public static int compare(short x, short y) {
    return x - y;
}

Solution:

If you try:

System.out.println(Long.MIN_VALUE - Long.MAX_VALUE);

or

System.out.println(Integer.MIN_VALUE - Integer.MAX_VALUE);

You will get 1 because of overflow(update: should be underflow here, as mentioned in another answer), which is incorrect.

However, with

System.out.println(Short.MIN_VALUE - Short.MAX_VALUE);

you will get correct value -65535, because short will be converted to int before - operation, which prevents the overflow.