delete vs undefined vs null

JavaScript performance comparison

Revision 54 of this test case created by

Preparation code

<script>
  o = {
   p: 1, a: 'a', b: 'b', c: 'c', d: 'd', e: 'e', f: 'f', g: 'g', h: 'h', i: 'i', j: 'j', test: 1234, test2: 1234, test4: 1234515, pa: 'hello', pb: 'hellob'
  };
  var id = 0
  
  function reset() {
   o.p = ++id;
  }
</script>
    

Test runner

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
delete object.property
var i;
for (i = 0; i < 100; i++) {
 delete o.p;
 reset();
};
pending…
delete object["property"]
var i;
for (i = 0; i < 100; i++) {
 delete o["p"];
 reset();
}
pending…
object.property = undefined
var i;
for (i = 0; i < 100; i++) {
 o.p = undefined;
 reset();
}
pending…
object["property"] = undefined
var i;
for (i = 0; i < 100; i++) {
 o["p"] = undefined;
 reset();
}
pending…
object.property = null
var i;
for (i = 0; i < 100; i++) {
 o.p = null;
 reset();
}
pending…
object["property"] = null
var i;
for (i = 0; i < 100; i++) {
 o["p"] = null;
 reset();
}
pending…

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Revisions

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