Run results for: Array Initialization: Constructor vs Literal

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:48.0) Gecko/20100101 Firefox/48.0

Browser: Firefox 48

Operating system: Mac OS X 10.11

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
Literal with push	194876.4 Ops/sec
Constructor() with push	141010.5 Ops/sec
Constructor(times) with push	85268.8 Ops/sec
Literal with index	131313.1 Ops/sec
Constructor() with index	126079.0 Ops/sec
Constructor(times) with index	143869.8 Ops/sec
Literal with push and overflow	135240.1 Ops/sec
Constructor() with push and overflow	136547.5 Ops/sec
Constructor(times) with push and overflow	79034.5 Ops/sec
Literal with index and overflow	146330.3 Ops/sec
Constructor() with index and overflow	141604.5 Ops/sec
Constructor(times) with index and overflow	157976.5 Ops/sec

Script Preparation code:

var times = 500;

var noOverflow = 0,
    overflow = 1;

Tests:

Literal with push
var arr = [], arrSize = times + noOverflow; for (var i = 0; i <= arrSize; i++) { arr.push(1337); }
Constructor() with push
var arr = new Array(), arrSize = times + noOverflow; for (var i = 0; i <= arrSize; i++) { arr.push(1337); }
Constructor(times) with push
var arr = new Array(times), arrSize = times + noOverflow; for (var i = 0; i <= arrSize; i++) { arr.push(1337); }
Literal with index
var arr = [], arrSize = times + noOverflow; for (var i = 0; i <= arrSize; i++) { arr[i] = 1337; }
Constructor() with index
var arr = new Array(), arrSize = times + noOverflow; for (var i = 0; i <= arrSize; i++) { arr[i] = 1337; }
Constructor(times) with index
var arr = new Array(times), arrSize = times + noOverflow; for (var i = 0; i <= arrSize; i++) { arr[i] = 1337; }
Literal with push and overflow
var arr = [], arrSize = times + overflow; for (var i = 0; i <= arrSize; i++) { arr.push(1337); }
Constructor() with push and overflow
var arr = new Array(), arrSize = times + overflow; for (var i = 0; i <= arrSize; i++) { arr.push(1337); }
Constructor(times) with push and overflow
var arr = new Array(times), arrSize = times + overflow; for (var i = 0; i <= arrSize; i++) { arr.push(1337); }
Literal with index and overflow
var arr = [], arrSize = times + overflow; for (var i = 0; i <= arrSize; i++) { arr[i] = 1337; }
Constructor() with index and overflow
var arr = new Array(), arrSize = times + overflow; for (var i = 0; i <= arrSize; i++) { arr[i] = 1337; }
Constructor(times) with index and overflow
var arr = new Array(times), arrSize = times + overflow; for (var i = 0; i <= arrSize; i++) { arr[i] = 1337; }

Run results for: Array Initialization: Constructor vs Literal

This test should measure performance of different array initialization types

Literal with push

Constructor() with push

Constructor(times) with push

Literal with index

Constructor() with index

Constructor(times) with index

Literal with push and overflow

Constructor() with push and overflow

Constructor(times) with push and overflow

Literal with index and overflow

Constructor() with index and overflow

Constructor(times) with index and overflow