Run results for: flatMap vs reduce with spread vs reduce with push vs for of vs push v2 ...

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser: Chrome 126

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

copy via slice

1.4M/s

copy via spread

110K/s

push(...arr)

64K/s

for...of

48K/s

reduce with push

36K/s

flatMap

6K/s

for i

3K/s

reduce with spread

33/s

View exact numbers

Script Preparation code:

var arr = Array(10_000).fill(0)

Tests:

reduce with spread
arr.reduce((acc, x) => [...acc, x], [])
flatMap
arr.flatMap(x => [x])
reduce with push
arr.reduce((acc, x) => { acc.push(x); return acc; }, [])
for...of
const acc = [] for (const x of arr) { acc.push(x); }
push(...arr)
const acc = [] acc.push(...arr);
copy via spread
const acc = [...arr];
copy via slice
const acc = arr.slice();
for i
const acc = [] const n = arr.length; for (let i = 0; i<n; i++) { acc[i] = arr[i]; }