Run results for: map initialisation

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser: Chrome 128

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

.forEach()

1.9M/s

.map()

1.7M/s

View exact numbers

Test name	Executions per second
✓ .forEach()	1,904,345 Ops/sec
.map()	1,710,896 Ops/sec

Script Preparation code:

var arr = [
  { a: 'Ghkfj', b: 'Yvtzq', c: 'Rwsde' },
  { a: 'Bpqwm', b: 'Sdfgh', c: 'Zxcvb' },
  { a: 'Olmnp', b: 'Iujkl', c: 'Qwerty' },
  { a: 'Cdsaf', b: 'Asdfg', c: 'Xcvbn' },
  { a: 'Qwerz', b: 'Cvbnm', c: 'Xcvbn' }
]

Tests:

.forEach()
const map = new Map(); arr.forEach(el => map.set(el.a, el));
.map()
const map = new Map(arr.map(el => [el.a, el]));

Run results for: map initialisation

measure map initialization with array or map

.forEach()

.map()