array vs object (v5)

Revision 5 of this benchmark created by Danny on

Description

Pulling array length reference out of the for loop.

Setup

var arr = [],
      i,
      obj = {};
      for(i = 0; i < 100; i = i + 1) {
        var item = {index: i};
        arr.push(item);
        obj[i] = item;
      }

Test runner

Ready to run.

Testing in
TestOps/sec
array
var arrLength = arr.length;
for (var x=0; x<arrLength; x++) {
    i = arr[x].index;
}
ready
object
for (var x=0; x<100; x++) {
    i = obj[x].index;
}
ready
object unknown length
var keys = Object.keys(obj);
for (var x = 0; x < keys.length; x++){
  i = obj[keys[x]].index;
}
ready

Revisions

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