Run results for: Various object iteration methods

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser: Chrome 141

Operating system: Windows

Device Platform: Desktop

Date tested: 9 months ago

Object.values, integer keys

597K/s

for..in w/ lookup, string keys

566K/s

Object.values, string keys

469K/s

Object.entries, string keys

206K/s

Object.keys w/ lookup, integer keys

107K/s

for..in w/ lookup, integer keys

77K/s

for..in w/ lookup, integer keys, null proto

77K/s

Object.entries, integer keys

44K/s

for..in w/ lookup, string keys, null proto

38K/s

Object.keys w/ lookup, string keys

24K/s

View exact numbers

Test name	Executions per second
✓ Object.values, integer keys	596,619 Ops/sec
for..in w/ lookup, string keys	566,013 Ops/sec
Object.values, string keys	469,029 Ops/sec
Object.entries, string keys	206,169 Ops/sec
Object.keys w/ lookup, integer keys	107,050 Ops/sec
for..in w/ lookup, integer keys	77,454 Ops/sec
for..in w/ lookup, integer keys, null proto	77,376 Ops/sec
Object.entries, integer keys	43,682 Ops/sec
for..in w/ lookup, string keys, null proto	38,032 Ops/sec
Object.keys w/ lookup, string keys	23,929 Ops/sec

Script Preparation code:

const bigObject_int = Object.fromEntries(Array(1000).fill(null).map((_,i) => [i, i]));
const bigObject_int_NoProto = Object.assign({__proto__:null}, bigObject_int);
const bigObject_str = Object.fromEntries(Array(1000).fill(null).map((_,i) => [`_${i}`, i]));
const bigObject_str_NoProto = Object.assign({__proto__:null}, bigObject_str);

Tests:

Object.keys w/ lookup, integer keys
let x = 0; for (const key of Object.keys(bigObject_int)) { x += bigObject_int[key]; }
Object.values, integer keys
let x = 0; for (const i of Object.values(bigObject_int)) { x += i; }
Object.entries, integer keys
let x = 0; for (const [_, i] of Object.entries(bigObject_int)) { x += i; }
for..in w/ lookup, integer keys
let x = 0; for (const key in bigObject_int) { x += bigObject_int[key]; }
for..in w/ lookup, integer keys, null proto
let x = 0; for (const key in bigObject_int_NoProto) { x += bigObject_int_NoProto[key]; }
Object.keys w/ lookup, string keys
let x = 0; for (const key of Object.keys(bigObject_str)) { x += bigObject_str[key]; }
Object.values, string keys
let x = 0; for (const i of Object.values(bigObject_str)) { x += i; }
Object.entries, string keys
let x = 0; for (const [_, i] of Object.entries(bigObject_str)) { x += i; }
for..in w/ lookup, string keys
let x = 0; for (const key in bigObject_str) { x += bigObject_str[key]; }
for..in w/ lookup, string keys, null proto
let x = 0; for (const key in bigObject_str_NoProto) { x += bigObject_str_NoProto[key]; }