How to get the difference between two integers

Question

I'm trying to make a program which uses areas and each area has an id (e.g.:1;1) and I'm trying to get the size of a specified area with comparing two ids but this method returns 1 as size.

 //Pos1 = -2;3 Pos2 = 0;1
 int x = Integer.valueOf(pos2.x).compareTo(pos1.x);
 int y = Integer.valueOf(pos2.y).compareTo(pos1.y);
 int size = Math.abs(x * y);

So how can I make this work?

Answer 1

compareTo is not supposed to return the exact difference between two values. From the docs:

Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Use

int x = Math.abs(pos2.x-pos1.x);
int y = Math.abs(pos2.y-pos1.y);
int size = x * y;

Answer 2

The result is 1 because compareTo() returns 0 if the arguments are equal, -1 if the first int is smaller than the second one and 1 if the second one is smaller (you can read more about it in the official docs).

--> You should not use this method for this purpose. Calculate the difference instead:

int x = pos2.x - pos1.x;
int y = pos2.y - pos1.y;
int size = Math.abs(x * y);