Question

In reviewing “Crossfilter” source I came across a function that used >>. Below is the function :

  // Similar to bisectLeft, but returns an insertion point which comes after (to
  // the right of) any existing entries of x in a.
  //
  // The returned insertion point i partitions the array into two halves so that
  // all v <= x for v in a[lo:i] for the left side and all v > x for v in
  // a[i:hi] for the right side.

  function bisectRight(a, x, lo, hi) {
    while (lo < hi) {
      var mid = lo + hi >> 1;
      if (x < f(a[mid])) hi = mid;
      else lo = mid + 1;
    }
    return lo;
  }

Google isn’t returning any results and I have never seen this before. Thanks in advance for the help.

Answer 1

Bitwise shift, see https://developer.mozilla.org/en/JavaScript/Reference/Operators/Bitwise_Operators