What is the JavaScript >>> operator and how do you use it?

Question

I was looking at code from Mozilla that add a filter method to Array and it had a line of code that confused me.

var len = this.length >>> 0;
         


        

Answer 1

That is the unsigned right bit shift operator. The difference between this and the signed right bit shift operator, is that the unsigned right bit shift operator (>>>) fills with zeroes from the left, and the signed right bit shift operator (>>) fills with the sign bit, thus preserving the sign of the numerical value when shifted.