Info

Simple test to check the difference in performance of JavaScript Math.floor() vs double bitwise NOT operator: ~~.

More info here: http://rocha.la/JavaScript-bitwise-operators-in-practice

Preparation code

 
<script>
  Benchmark.prototype.setup = function() {
    var numbers = [];
    
    //generate amount random numbers
    for (var i = 0; i < 100000; i++) {
      numbers[numbers.length] = Math.floor(Math.random()*100000)/10000;
    }
  };
</script>

Test runner

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Java applet disabled.

var test;
for (var i = 0; i < 100000; i++) {
  test = Math.floor(numbers[i]);
}

var test;
for (var i = 0; i < 100000; i++) {
  test = ~~ (numbers[i]);
}

var test;
for (var i = 0; i < 100000; i++) {
  test = (numbers[i]) <<0;
}

var test;
for (var i = 0; i < 100000; i++) {
  test = numbers[i] | 0;
}

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Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

• Revision 1: published by rochal on 26th November 2011
• Revision 2: published on 8th January 2012
• Revision 3: published on 2nd September 2012
• Revision 5: published on 18th January 2013
• Revision 6: published on 21st January 2013
• Revision 7: published on 21st January 2013
• Revision 8: published by Cong Liu on 20th February 2013

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