Performance of Array vs. Object (v29)

Revision 29 of this benchmark created by Dave on

Setup

var arr = [],
      i,
      obj = {};
  for(i = 0; i < 10000; i += 1) {
      var o = {payload:i};
      arr.push(o);
      obj[i] = o;
  }

Test runner

Ready to run.

Testing in
TestOps/sec
Descending greater than -1
var sum = 0;
for (var x=arr.length-1; x>-1; --x) {
    sum += arr[x].payload
}
ready
Array Performance
var sum = 0;
for (var x=0; x<arr.length; ++x) {
    sum += arr[x].payload
}
ready
Object Performance using known length
var sum = 0;
for (var x=0; x<10000; ++x) {
    sum += obj[x].payload
}
ready
Object Performance
var sum = 0;
for (var x in obj) {
    sum += obj[x].payload;
}
ready
Using Object.keys()
var sum = 0;
var keys = Object.keys(obj);
for (var x=0; x<keys.length; ++x) {
    sum += obj[keys[x]].payload
}
ready
Array with cached length
var sum = 0;
for (var x=0, len = arr.length; x<len; ++x) {
    sum += arr[x].payload
}
ready
Descending Array
var sum = 0;
for (var x=arr.length-1; x>=0; --x) {
    sum += arr[x].payload
}
ready

Revisions

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