Question

An example of it being used is here

boundsCentre = new Vector3D(stageWidth >> 1,stageHeight >> 1, 200.0);

Thanks.

Answer 1

>> is the right bit-shifting operator. a >> b will shift a‘s bit values b bits to the right.

if a = 8 and b = 2, a >> b will produce 2 because a is represented by 1000, shifted 2 places is 10 which represents 2 in binary.

More importantly, because ActionScript is an ECMAScript variant, values of type Number will be converted from a 64-bit representation to a 32-bit representation and then shifted. Additionally, (AFAIK, can’t seem to find it in the reference) bit-shift overflows are undefined in ECMAScript.

stageWidth >> 1 essentially divides the stageWidth by 2, which means it’s a vector to the center of the stage. In other languages x >> 1 is a faster method of division by 2, but in ECMAScript, there is no significant performance change, and the possibility of ambiguity. Because of this it is better to just code the desired effect as:

stageWidth / 2

It is much more understandable that way.