Info

for vs while

Preparation code

 
<script>
  Benchmark.prototype.setup = function() {
    var result = 0,
        steps = 100;
  };
</script>

Test runner

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var result = 0;
for (var i = steps - 1; i >= 0; i--) {
  result += i;
}

var result = 0;
for (var i = steps; i--;) {
  result += i;
}

var i = steps, result =0;
while (i--) {
  result += i;
}

var result = 0;
for (var i = 0; i < steps; i++) {
  result += i;
}

var result = 0;
for (var i = 0; i < steps; i++) result += i;

var i = 0, result =0;
for (;;) {
  result += i++;
  if (i == steps) break;
}

var i, result = 0;
for (i = steps - 1; i; i--) {
  result += i;
}

var i = steps, result = 0;
while (i) {
  result = result + i;
  i = ~-i;
}

//var x = "Read my blog about it at http://milan.adamovsky.com";

// Seems to work best for IE
var i = steps, result = 0;
redo:
while (i--) {
  result = result + i;
  continue redo;
}

var i = steps, result = 0;

// Seems to work best for non-IE
redo:
while (i) {
  result = result + i;
  i--;
  continue redo;
}

Compare results of other browsers

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 antimatter15 on 3rd August 2010
• Revision 2: published by David Calhoun on 17th August 2010
• Revision 3: published by Leonardo Dutra on 17th August 2010
• Revision 4: published by Anthony M on 5th May 2011
• Revision 5: published on 28th September 2011
• Revision 6: published on 29th September 2011
• Revision 7: published on 23rd November 2011
• Revision 8: published by devu on 23rd November 2011
• Revision 9: published by Jörn Berkefeld on 25th November 2011
• Revision 10: published by Milan Adamovsky on 15th December 2011
• Revision 11: published by Milan Adamovsky on 15th December 2011 and last updated on 16th December 2011
• Revision 14: published by Rick Waldron on 16th December 2011
• Revision 15: published by Jeff Tierney on 16th December 2011
• Revision 16: published on 16th December 2011
• Revision 17: published on 16th December 2011
• Revision 18: published by Milan Adamovsky on 16th December 2011
• Revision 20: published on 16th December 2011
• Revision 21: published by Milan Adamovsky on 16th December 2011
• Revision 22: published by Mayhem on 19th December 2011
• Revision 23: published by Mike Lee on 19th December 2011
• Revision 24: published by Milan Adamovsky2 on 29th December 2011
• Revision 25: published on 5th January 2012
• Revision 26: published on 5th January 2012
• Revision 27: published on 15th February 2012
• Revision 28: published by Milan Adamovsky on 17th February 2012

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