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: 8 months ago

Test name	Executions per second
Object.keys w/ lookup, integer keys	107050.5 Ops/sec
Object.values, integer keys	596619.1 Ops/sec
Object.entries, integer keys	43681.6 Ops/sec
for..in w/ lookup, integer keys	77454.4 Ops/sec
for..in w/ lookup, integer keys, null proto	77376.0 Ops/sec
Object.keys w/ lookup, string keys	23929.5 Ops/sec
Object.values, string keys	469029.4 Ops/sec
Object.entries, string keys	206169.1 Ops/sec
for..in w/ lookup, string keys	566013.3 Ops/sec
for..in w/ lookup, string keys, null proto	38031.9 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]; }

Run results for: Various object iteration methods

Object.keys w/ lookup, integer keys

Object.values, integer keys

Object.entries, integer keys

for..in w/ lookup, integer keys

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

Object.keys w/ lookup, string keys

Object.values, string keys

Object.entries, string keys

for..in w/ lookup, string keys

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