ES6 Map vs Object properties

JavaScript performance comparison

Revision 88 of this test case created by jin

Preparation code

<script>
function randomString()
{
    var text = "";
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    for( var i=0; i < 5; i++ )
        text += possible.charAt(Math.floor(Math.random() * possible.length));

    return text;
}

var preComputedRandomKeys = [];
var preComputedRandomVals = [];

for (var i=0; i < 100000; i++) {
   preComputedRandomKeys[i] = randomString();
   preComputedRandomVals[i] = randomString();
}
</script>
      
<script>
Benchmark.prototype.setup = function() {
  var map = new Map();
  var obj = {};
  
  var map2 = new Map();
  var obj2 = {};
  
  for (var i=0; i < 100000; i++) {
     map2.set(preComputedRandomKeys[i], preComputedRandomVals[i]);
     obj2[preComputedRandomKeys[i]] = preComputedRandomVals[i];
  }
  
  for (var i=0; i < 100000; i++) {
     map2.set(preComputedRandomKeys[i], map2.get(preComputedRandomKeys[i]));
     obj2[preComputedRandomKeys[i]] = obj2[preComputedRandomKeys[i]];
  }

};
</script>

Test runner

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
map.set(key,val)
for (var i=0; i < 100000; i++) {
   var key = preComputedRandomKeys[i];
   var val = preComputedRandomVals[i];
   map.set(key, val);
}
pending…
obj[key] = val;
for (var i=0; i < 100000; i++) {
   var key = preComputedRandomKeys[i];
   var val = preComputedRandomVals[i];
   obj[key] = val;
}
pending…
Iterate Map
var valx;
for (var [key, val] of map2.entries()) {
  valx = val;
}
pending…
Iterate Object
var key;
for (key in obj2) {
  if (obj2.hasOwnProperty(key))
    var val = obj2[key];
}
pending…
val = map.get(key)
for (var i=0; i < 100000; i++) {
   var val = map2.get(preComputedRandomKeys[i]);
}
pending…
val = obj[key]
for (var i=0; i < 100000; i++) {
   var val = obj2[preComputedRandomKeys[i]];
}
pending…

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