Run results for: isArray

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser: Chrome 128

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

Array.isArray

12.0M/s

Object.prototype.toString

5.8M/s

[].constructor

4.6M/s

instanceof

4.4M/s

View exact numbers

Test name	Executions per second
✓ Array.isArray	12,011,007 Ops/sec
Object.prototype.toString	5,760,848 Ops/sec
[].constructor	4,602,691 Ops/sec
instanceof	4,448,780 Ops/sec

Script Preparation code:

var toStr = Object.prototype.toString
	
function toStrCase(obj){
  return toStr.call(obj) === '[object Array]'
}
function consCase(obj){
  return obj && obj.constructor === Array
}
function instCase(obj){
  return obj && obj instanceof Array
}
var isArray = Array.isArray

Tests:

Array.isArray
isArray([])
instanceof
instCase([])
[].constructor
consCase([])
Object.prototype.toString
toStrCase([])

Array.isArray vs Object.prototype.toString vs [].constructor vs instanceof

Array.isArray

instanceof

[].constructor

Object.prototype.toString