preallocating Array

JavaScript performance comparison

Revision 30 of this test case created by

Preparation code

  var N = 1000;
  var dummy = new Array(N); // prevents garbage collecting hidden class in Chrome

Test runner

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
var a = [];
a.length = N;
for (var i = 0; i < N; ++i) {
 a[i] = Math.random() > 0.5 ? "foo" : 3;
// .push on new Array(N) appends elements after N index.


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