Array.prototype.push.apply vs concat (v5)

Revision 5 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 x = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
      y = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
  var arrPush = Array.prototype.push;
</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#push.apply
var a = x.slice(0),
    b = y.slice(0);

Array.prototype.push.apply(a, b);
ready
Array#push with loop
var a = x.slice(0),
    b = y.slice(0),
    i = 0,
    c = b.length;

for (; i < c; ++i) {
  a.push(b[i]);
}
ready
Cached Array#push
var a = x.slice(0),
    b = y.slice(0);

arrPush.apply(a, b);
ready
Splice
var a = x.slice(0),
    b = y.slice(0);
a.splice.apply(b, [b.length, 9e9].concat(b))
ready

Revisions

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