Performance of for-in loop vs for loop over Object.keys (v260)

Revision 260 of this benchmark created 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
For inner variable
var sum = 0;
for (var x=0,keys=Object.keys(obj); x<keys.length; ++x) {
    sum += obj[keys[x]].payload
}
ready
For
var sum = 0
for (var x=0; x<Object.keys(obj).length; ++x) {
    sum += obj[keys[x]].payload
}
ready
for-in loop
var sum = 0;
for (var x in obj) {
    sum += obj[x].payload;
}
ready
for loop over Object.keys
var sum = 0;
var keys = Object.keys(obj);
for (var x=0; x<keys.length; ++x) {
    sum += obj[keys[x]].payload
}
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.