Info

Typeof check when looking for number, vs unary +

Preparation code

 
<script>
  Benchmark.prototype.setup = function() {
    var toCheck = 42;
    var a = 0;
    
    var numString = 'number';
  };
</script>

Test runner

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

Java applet disabled.

if (typeof numString === 'number') {
 a++;
}

if (typeof numString === numString) {
 a++;
}

if (numString === +numString) {
 a++;
}

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 Jarrod Overson on 19th February 2013
• Revision 2: published on 2nd March 2013
• Revision 3: published on 14th March 2013
• Revision 4: published 1 week ago
• Revision 5: published 1 week ago

0 comments