Question

I want to make an If statement:

if(x == y+n)

{ }

n = [-20...20]

where n can be any integer value from -20 to 20.

How to do this in java?

In android I am trying to “synchronize” the ontouch listener to drawView. So I mean an image randomly appears I want to perform a certain action when the image appears….So the “touch” on the screen is pretty precise…

----DrawView Class---

setX(rand.nextInt(width-20));
setY(rand.nextInt(height-20));
canvas.drawBitmap(b, getX(), getY(), paint);


public boolean onTouch(View arg0, MotionEvent event) {
if (event.getX() == DrawView.getX()|| event.getY() == DrawView.getY())
{
Certian action...
} 
}

so how can I include, DrawView.getX()+[-20…20] and DrawView.getY()+[-20…20]?

Answer 1

If I understand your question correctly, you might mean this:

int n = x - y;
if (n >= -20 && n <= 20) {
    // etc...
}

For your specific range, you can simplify this expression by using Math.abs:

if (Math.abs(x - y) <= 20) {
    // etc ...
}