is undefined (v2)

Revision 2 of this benchmark created by Nige White on

Preparation HTML

<script>
  var undef, undef2, count = 0,
      testObj = {};
  
  function isUndefined1(x) {
    return x === undefined;
  }
  
  function isUndefined2(x) {
    return typeof undef === 'undefined';
  }
  
  function isUndefined3(x) {
    return typeof x == 'undefined';
  }
  
  function isUndefined4(x) {
    return x === undef2;
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
strict eq undefined
if (undef === undefined) {
  ++count;
}
ready
typeof strict eq undefined
if (typeof undef === 'undefined') {
  ++count;
}
ready
typeof eq undefined
if (typeof undef == 'undefined') {
  ++count;
}
ready
strict eq undef var
if (undef === undef2) {
  ++count;
}
ready
isUndefined1
if (isUndefined1(undef)) {
  ++count;
}
ready
isUndefined2
if (isUndefined2(undef)) {
  ++count;
}
ready
isUndefined3
if (isUndefined3(undef)) {
  ++count;
}
ready
isUndefined4
if (isUndefined4(undef)) {
  ++count;
}
ready
Strict prop test
if (testObj.x === undefined) {
  ++count;
}
ready
prop in obj test
if (!('x' in testObj)) {
  ++count;
}
ready

Revisions

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

  • Revision 1: published by Don on
  • Revision 2: published by Nige White on