for in vs typeof

JavaScript performance comparison

Revision 3 of this test case created

Preparation code

 
<script>
Benchmark.prototype.setup = function() {
    var obj = {
      "foo":"bar",
      "what":"ok",
      "party" : "whatever"
    }
};
</script>

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Testing in unknown unknown
Test Ops/sec
for in
if ("thing" in obj) {
 var b = obj["thing"];
}
pending…
typeof
if (typeof(obj['thing']) !== "undefined") {
 var b = obj["thing"];
}
pending…

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