Run results for: isArray

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.4 Safari/605.1.15

Browser: Safari 18

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

instanceof

506.3M/s

Array.isArray

483.0M/s

[].constructor

113.8M/s

Object.prototype.toString

105.2M/s

View exact numbers

Test name	Executions per second
✓ instanceof	506,267,712 Ops/sec
Array.isArray	483,002,528 Ops/sec
[].constructor	113,814,080 Ops/sec
Object.prototype.toString	105,179,344 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