Benchmark: for x of array & for k in object

Script Preparation code:

var obj = {}
var arr = [] 
for (var i = 0; i<100000; i++) {
   var val = Math.random()
   obj[i] = val
   arr[i] = val
}
var wtf
function loopObj () {
  for (var k in obj) {
    wtf = obj[k]
  }
}

function loopArr () {
  for (var val of arr) {
    wtf = val
  }
}

console.log('prepare=> obj =', obj, '; arr =', arr)

Tests:

for key in object
for (var k in obj) { wtf = obj[k] }
for val of array
for (var val of arr) { wtf = val }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for key in object
for val of array

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:73.0) Gecko/20100101 Firefox/73.0

Browser/OS: Firefox 73 on Linux

View result in a separate tab

Test name	Executions per second
for key in object	35.3 Ops/sec
for val of array	847.7 Ops/sec

for x of array & for k in object (version: 0)

Comparing performance of: for key in object vs for val of array

Created: 4 years ago by: Registered User

Jump to the latest result

for key in object

for val of array

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A