caching length (v94)

Revision 94 of this benchmark created by Turiya on

Setup

var arr = [];
    for (var i = 0; i < 1000; i++) {
      arr[i] = Math.random();
    }

Test runner

Ready to run.

Testing in
TestOps/sec
cached
for (var i = 0, len = arr.length; i < len; i++) {
  arr[i] *= 2;
}
ready
not cached
for (var i = 0; i < arr.length; i++) {
  arr[i] *= 2;
}
ready
u wot m8
var len = 2;
len *= arr.length;
len -= len / 2;
for (var i = 0; i < len; i++) {
  arr[i] *= 2;
}
ready
while loop
var len = arr.length;
while (len--) {
  arr[len] *= 2;
}
ready
do-while loop
var len = arr.length;
do {
  arr[len] *= 2;
} while (len--);
ready
Prefix Increment
for (var i = 0; i < arr.length; ++i) {
  arr[i] *= 2;
}
ready
Prefix + Cached
for (var i = 0, len = arr.length; i < len; ++i) {
  arr[i] *= 2;
}
ready
Array map
arr.map(function(el) {
  return el * 2;
});
ready
.shift()
var el;
while (el = arr.shift()) {
  el *= 2;
}
ready
.pop()
var el;
arr = arr.reverse();
while (el = arr.pop()) {
  el *= 2;
}
ready
compare new node
var val;
var hash = Object.create(null);
var array = Object.create(arr);
while (val = array.shift()) {
  hash[val] = true;
}
ready
compare new node 2
var hash = Object.create(null);

  for (var i = 0; i < arr.length; i++) {
    var val = arr[i];
    hash[val] = true;
  }
ready
for in
for (var idx in arr) {
  arr[idx] *= 2;
}
ready

Revisions

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