ES6 Map vs Object properties (v22)

Revision 22 of this benchmark created on

Description

Compare native Map implementation vs using an object as a hash map.

Preparation HTML

<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 JSON.parse(JSON.stringify(text));
}
</script>

Setup

var J = 10;
    var keys = [];
    
    for (var i=0; i < 1000; i++) {
      keys.push(randomString());
    }
    
    var mixedkeys = [];
    for (var i=0; i < 500; i++) {
      mixedkeys.push(randomString());
      mixedkeys.push(i);
    }
    
    var map = new Map();
    var obj = Object.create(null);
    obj.x = true;
    delete obj.x;
    
    for (var i = 0; i < 10; i++) {
      map.set(keys[i], i);
      obj[keys[i]] = i;
    }
    var x = 0;

Test runner

Ready to run.

Testing in
TestOps/sec
map.set(key,val)
var map = new Map();
for (var j = 0; j < J; j++)
for (var i = 0; i < keys.length; i++) {
  map.set(keys[i], i);
}
 
ready
obj[key] = val;
var obj = Object.create(null);
obj.x = true;
delete obj.x;

for (var j = 0; j < J; j++)
for (var i = 0; i < keys.length; i++) {
  obj[keys[i]] = i;
}
 
ready
map.get non-existant
for (var j = 0; j < J; j++)
for (var i = 0; i < keys.length; i++) {
  if (map.get(keys[i]) !== void 0) x++;
}
 
ready
object get non-existant
for (var j = 0; j < J; j++)
for (var i = 0; i < keys.length; i++) {
  if (obj[keys[i]] !== void 0) x++;
}
ready

Revisions

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