Java Bit Manipulation - What does (num >>= 1) do?

Question

I was looking at some code that outputs a number to the binary form with prepended 0s.

    byte number = 48;
    int i = 256; //max number * 2
    while( (i >>= 1) > 0) {
        System.out.print(((number & i) != 0 ? "1" : "0"));
    }

and didn't understand what the i >>= 1 does. I know that i >> 1 shifts to the right by 1 bit but didn't understand what the = does and as far as I know, it is not possible to do a search for ">>=" to find out what it means.

Solution

i >>= 1 is just shorhand for i = i >> 1 in the same way that i += 4 is short for i = i + 4

EDIT: Specifically, those are both examples of compound assignment operators.

Comments

[Lawrence Dol]

And, specifically, it's a sign-extending shift.

[yasouser]

Mathematically right shifting a number by 1 is equivalent to the dividing the number by 2.