pre-allocated arrays

JavaScript performance comparison

Revision 20 of this test case created by NibbleByte

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Test Ops/sec
empty literal
var arr = [];
for (var i = 0; i < 1000000; i++) {
  arr[i] = i;
}
pending…
pre-allocated array
var arr = new Array(1000000);
for (var i = 0; i < 1000000; i++) {
  arr[i] = i;
}
pending…
pre-defined array
var arr = new Array;
for (var i = 0; i < 1000000; i++) {
  arr[i] = i;
}
pending…
empty literal, push-grown
var arr = [];
for (var i = 0; i < 1000000; i++) {
  arr.push(i);
}
pending…
empty literal, length-allocated
var arr = [];
arr.length = 1000000;
for (var i = 0; i < 1000000; i++) {
  arr[i] = i;
}
pending…

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