jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.

jsperf.com URLs are mirrored at the same path, e.g:

https://jsperf.com/negative-modulo/2

Can be accessed at:

https://jsperf.app/negative-modulo/2

"Type of undefined" vs "=== undefined" (v60)

Revision 60 of this benchmark created by darren on March 23, 2015

Setup

var a = [{
      lol: "skates"
    }],
      b = [],
      c = [{
        lol: "skates"
      }],
      d = [],
      e = {}, u;

Test runner

Ready to run.

Testing in
Test		Ops/sec
typeof undefined	`typeof a === 'undefined';`	ready
=== undefined	`a === undefined;`	ready
=== undefined(local)	`a === u;`	ready
void 0	`a === void 0;`	ready
not	`!a;`	ready

Revisions

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

Revision 1: published by ukyo on April 28, 2012
Revision 2: published by ukyo on May 13, 2012
Revision 3: published on May 14, 2012
Revision 4: published by Bombo on June 6, 2012
Revision 6: published by Mihai Bazon on September 16, 2012
Revision 9: published on March 12, 2013
Revision 11: published by Raymond on April 23, 2013
Revision 12: published on April 23, 2013
Revision 14: published by Raymond on May 20, 2013
Revision 15: published on May 20, 2013
Revision 18: published on July 18, 2013
Revision 19: published on July 29, 2013
Revision 20: published on July 31, 2013
Revision 23: published by hellraiser on September 18, 2013
Revision 25: published by Tomas Corral on October 8, 2013
Revision 26: published on October 8, 2013
Revision 27: published on December 5, 2013
Revision 29: published on December 26, 2013
Revision 30: published on January 24, 2014
Revision 31: published on February 21, 2014
Revision 32: published on February 21, 2014
Revision 33: published on February 21, 2014
Revision 34: published on March 17, 2014
Revision 37: published on May 13, 2014
Revision 38: published by r on May 15, 2014
Revision 39: published on May 20, 2014
Revision 40: published by PAEz on May 27, 2014
Revision 41: published on May 27, 2014
Revision 42: published on June 2, 2014
Revision 43: published on June 11, 2014
Revision 44: published by Oscar Campbell on June 21, 2014
Revision 45: published on July 8, 2014
Revision 46: published on July 8, 2014
Revision 47: published on July 8, 2014
Revision 48: published on July 8, 2014
Revision 49: published on July 8, 2014
Revision 50: published on July 12, 2014
Revision 51: published by Simon on August 22, 2014
Revision 52: published by hoochieminh on September 19, 2014
Revision 53: published on October 28, 2014
Revision 54: published on November 26, 2014
Revision 55: published on December 31, 2014
Revision 56: published on January 26, 2015
Revision 57: published on February 4, 2015
Revision 58: published on February 27, 2015
Revision 59: published on February 27, 2015
Revision 60: published by darren on March 23, 2015
Revision 62: published on April 11, 2015
Revision 63: published on April 12, 2015
Revision 64: published on April 12, 2015
Revision 65: published on April 18, 2015
Revision 66: published by bskaplou on April 20, 2015
Revision 67: published by Ben L. Titzer on May 5, 2015
Revision 68: published by Ben L. Titzer on May 5, 2015
Revision 69: published by Ben L. Titzer on May 5, 2015
Revision 70: published by Adrian Bartholomew on May 9, 2015
Revision 71: published by Fuwei Chin on June 13, 2015
Revision 72: published on September 29, 2015
Revision 73: published on September 29, 2015
Revision 76: published by Alexander on December 8, 2015
Revision 77: published on December 28, 2015
Revision 78: published on January 7, 2016