Java integer cyclic iteration shorthand

Question

When coding I find myself doing the following very often:

corner++; 
if(corner == 4) corner = 0;

Is there anyway do this in one line?

In this example corner should be 0, 1, 2, 3, 0, 1, 2, 3, 0....

Answer 1

You can use this short and kind of readable line (Demo):

corner = (corner + 1) % 4;

Or, even a tiny bit shorter (Demo):

corner = ++corner % 4;

Answer 2

Use remainder. It's two lines but clean.

corner++;
corner %= 4;

Answer 3

You can do this:

corner = ++corner == 4 ? 0 : corner;

This would give you the possibility to assign something else to the corner variable in case your corner == 4 test didn't pass.

Answer 4

I use:

if (++corner == 4) corner = 0;

Answer 5

It is not so obvious but much faster, since division generally executes slower than any bitwise operation.

corner = ++corner & 3;

EDIT: And surprisingly I discovered one more awesome way to make cycling - using shifts, and it runs even faster!

corner = ++corner << 30 >>> 30;

And this trick only works for any power of 2.

This benchmark shows all the results (though it's javascript, not java)