Array.prototype.push.apply vs concat (v50)

Revision 50 of this benchmark created on

Description

This page tests speed of two different methods for array concatenation. Array method concat() has no side effects (it creates a new array to store its result in), while Array.prototype.push.apply(A, [1, 2, ...]) extends the array A.

Preparation HTML

<script>
  var len = 1500;
  var x = new Array(len),
      y = new Array(len);
  for (var i = 0; i < len; i++) {
   x[i] = i;
   y[i] = -i;
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
concat
var a = x.slice(0),
    b = y.slice(0);

a = a.concat(b);
ready
Array.prototype.push.apply
var a = x.slice(0),
    b = y.slice(0);

Array.prototype.push.apply(a, b);
ready
Array#push in forEach
var a = x.slice(0),
    b = y.slice(0);

b.forEach(function (item) {
  a.push(item);
});
ready

Revisions

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