Loops (v125)

Revision 125 of this benchmark created on

Preparation HTML

<script>
  var arr = new Array(5);
  var obj = {}
  for (var i = 0, len = arr.length; i < len; i++) {
    obj[i] = null;
  }

  function advancedLoop(data, callback) {
    for (var i = 0, j; undefined !== (j = arr[i]); i++) {
      callback(j);
    };
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
while loop that imitates a for loop
var i = 0;
while (i < arr.length) {
  arr[i];
  i++;
};
ready
while loop that imitates a for loop, caching the length
var i = 0,
    len = arr.length;
while (i < len) {
  arr[i];
  i++;
};
ready
Reverse while loop
var i = arr.length;
while (i--) {
  arr[i];
};
ready
Reverse while loop without implicit ToBoolean
var i = arr.length;
while (i-- > 0) {
  arr[i];
};
ready
Reverse do … while loop
var i = arr.length;
do {
  arr[i];
} while (i--);
ready
Reverse for loop
for (var i = arr.length; i--;) {
  arr[i];
};
ready
Old ’n’ busted for loop
for (var i = 0; i < arr.length; ++i) {
  arr[i];
};
ready
Old ’n’ busted for loop, caching the length
for (var i = 0, len = arr.length; i < len; ++i) {
  arr[i];
};
ready
Cool guy loop
for (var i = -1; ++i < arr.length;) {
  arr[i];
};
ready
Cool guy loop, caching the length
for (var i = -1, len = arr.length; ++i < len;) {
  arr[i];
};
ready
Native Array#forEach implementation
arr.forEach(function(x) {
  x;
});
ready
Native Array#forEach implementation with named function
function foo(x) {
  x;
};
arr.forEach(foo);
ready
For In
for (i in arr) {
  arr[i]
}
ready
For In
for (i in obj) {
  obj[i]
}
ready
For loop with assignation as condition
for (var i = 0, j; undefined !== (j = arr[i]); i++) {
  j;
};
ready
For loop with assignation as condition and with callback
advancedLoop(arr, function(i) {
  i;
});
ready

Revisions

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