operators - What does << mean in Java?

Question

I can't find out what << means in Java because I can't search for it on Google - I am absolutely lost!

The code in question is:

public int getRGB() {
    return ((red << 16) | (green << 8) | blue);
}

It's taken from: http://java.sun.com/docs/books/tutorial/essential/concurrency/example/ImmutableRGB.java

I would really appreciate someone telling me, thanks!

Answer 1

Left shift of the bits

If red == 4 (which in binary is: 00000100) then red << 16 will insert sixteen 0-bits at its right, yielding: 000001000000000000000000 which is 262144 in decimal