javascript - Math.random and arithmetic shift -

if have following code in javascript:

var index1 = (math.random() * 6) >> 0; var index2 = math.floor(math.random() * 6); 

the results index1 or index2 anywhere between 0 , 6.

i must confused understanding of >> operator. thought using arithmetic shift results index1 anywhere between 1 , 6.

i noticing, don't need use math.floor() or math.round() index1 if use >> operator.

i know can achieve adding 1 both indexes, hoping there better way of ensuring results 1 6 instead of adding 1.

i'm aware bitwise operators treat operands sequence of 32 bits (zeros , ones), rather decimal, hexadecimal, or octal numbers. example, decimal number 9 has binary representation of 1001. bitwise operators perform operations on such binary representations, return standard javascript numerical values.

update:

i saw original usage in caat tutorial on line 26 , wondering whether return random number between 1 , 6 , seems ever return random number between 0 , 6. never see anim1.png fish image!

thank in advance enlightenment.

wikipedia says '(arithmetic right shifts negative numbers equivalent division using rounding towards 0 in one's complement representation of signed numbers used historic computers.)'

not answer, idea >> 0 specific , shouldn't used in general getting range between 1 , 6.

most people tell do

 math.floor((math.random()*10)+1);