Benchmark: Iterating over objects and maps

Iterating over objects and maps (version: 3)

Comparing performance of: for..of destructured with Object.entries() vs for..of undestructured with Object.entries() vs for..in vs for..of destructured with Object.entries() (with prototype) vs for..of undestructured with Object.entries() (with prototype) vs for..in (with prototype) vs for..of destructured with map vs for..of undestructured with map vs .forEach with Object.entries() vs .forEach with Object.entries() (with prototype) vs .forEach with map

Created: 4 years ago by: Registered User

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Script Preparation code:

var obj = Object.create(null);
var obj2 = {};
var map = new Map();
for (let i = 0;i < 10000; i++) {
  let j
  const n = Math.floor(Math.random() * 100)
  if (n > 26) {
    j = n
  } else {
    j = String.fromCharCode('a'.charCodeAt(0) + n);
  }
  obj[i] = j;
  obj2[i] = j;
  map.set(i, j);
}

Tests:

for..of destructured with Object.entries()
for (const [key, val] of Object.entries(obj)) { const keyval = key + val; }
for..of undestructured with Object.entries()
for (const entry of Object.entries(obj)) { const key = entry[0]; const val = entry[1]; const keyval = key + val; }
for..in
for (const key in obj) { const val = obj[key]; const keyval = key + val; }
for..of destructured with Object.entries() (with prototype)
for (const [key, val] of Object.entries(obj2)) { const keyval = key + val; }
for..of undestructured with Object.entries() (with prototype)
for (const entry of Object.entries(obj2)) { const key = entry[0]; const val = entry[1]; const keyval = key + val; }
for..in (with prototype)
for (const key in obj2) { const val = obj[key]; const keyval = key + val; }
for..of destructured with map
for (const [key, val] of map) { const keyval = key + val; }
for..of undestructured with map
for (const entry of map) { const key = entry[0]; const val = entry[1]; const keyval = key + val; }
.forEach with Object.entries()
Object.entries(obj).forEach(([key, val]) => { const keyval = key + val; });
.forEach with Object.entries() (with prototype)
Object.entries(obj2).forEach(([key, val]) => { const keyval = key + val; });
.forEach with map
map.forEach((key, val) => { const keyval = key + val; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for..of destructured with Object.entries()
for..of undestructured with Object.entries()
for..in
for..of destructured with Object.entries() (with prototype)
for..of undestructured with Object.entries() (with prototype)
for..in (with prototype)
for..of destructured with map
for..of undestructured with map
.forEach with Object.entries()
.forEach with Object.entries() (with prototype)
.forEach with map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.6 Safari/605.1.15

Browser/OS: Safari 16 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
for..of destructured with Object.entries()	354.6 Ops/sec
for..of undestructured with Object.entries()	434.6 Ops/sec
for..in	509.2 Ops/sec
for..of destructured with Object.entries() (with prototype)	222.0 Ops/sec
for..of undestructured with Object.entries() (with prototype)	217.6 Ops/sec
for..in (with prototype)	230.9 Ops/sec
for..of destructured with map	853.4 Ops/sec
for..of undestructured with map	1213.6 Ops/sec
.forEach with Object.entries()	158.1 Ops/sec
.forEach with Object.entries() (with prototype)	344.6 Ops/sec
.forEach with map	4509.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

Related benchmarks:

Iterating over objects and maps (version: 3)

Created: 4 years ago by: Registered User

Jump to the latest result

for..of destructured with Object.entries()

for..of undestructured with Object.entries()

for..in

for..of destructured with Object.entries() (with prototype)

for..of undestructured with Object.entries() (with prototype)

for..in (with prototype)

for..of destructured with map

for..of undestructured with map

.forEach with Object.entries()

.forEach with Object.entries() (with prototype)

.forEach with map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):