Preparation code

<script src="//ajax.googleapis.com/ajax/libs/prototype/1.7/prototype.js">
</script>
<script>
  Benchmark.prototype.setup = function() {
    var a1 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
        a2 = [0, 2, 4, 8];
    
    Array.prototype.intersect2 = function intersect2(array) {
      return this.uniq().findAll(function(item) {
        return array.detect(function(value) {
          return item === value;
        }) >= 0;
      });
    };
    
    Array.prototype.intersect3 = function intersect3(array) {
      return this.uniq().filter(function(item) {
        return array.indexOf(item) !== -1;
      });
    };
    
    Array.prototype.intersect4 = function intersect4(array) {
      var r = [],
          b = this.concat([]).sort().uniq(true).concat(array.concat([]).sort().uniq(true)).sort(),
          x = b.length;
      if (x > 0) {
        for (; --x;) {
          if (b[x] === b[x - 1] && r[0] !== b[x]) {
            r.unshift(b[x]);
          }
        }
      }
      return r;
    };
    
    Array.prototype.intersect5 = function intersect5(array) {
      var r = [],
          x, b = this.concat([]).sort().uniq(true).concat(array.concat([]).sort().uniq(true)).sort(),
          i = b.length;
      if (i > 0) {
        for (; --i;) {
          if (b[i] === b[i - 1] && x !== b[i]) {
            x = b[i];
            r.unshift(x);
          }
        }
      }
      return r;
    };
  };
</script>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

a1.intersect(a2)

a1.intersect2(a2)

a1.intersect3(a2)

a1.intersect4(a2)

a1.intersect5(a2)

You can edit these tests or add even more tests to this page by appending /edit to the URL.

Compare results of other browsers

0 comments