Run results for: Array initialization: preallocate vs push vs preallocate & fill

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:146.0) Gecko/20100101 Firefox/146.0

Browser: Firefox 146

Operating system: Windows

Device Platform: Desktop

Date tested: 6 months ago

Preallocate

18K/s

Push

17K/s

Index

15K/s

Preallocate & fill

12K/s

View exact numbers

Tests:

Preallocate
var N = 10000; var result = new Array(N); for (var i = 0; i < N; i++) { result[i] = i * 2; }
Preallocate & fill
var N = 10000; var result = new Array(N).fill(0); for (var i = 0; i < N; i++) { result[i] = i * 2; }
Push
var N = 10000; var result = []; for (var i = 0; i < N; i++) { result.push(i * 2); }
Index
var N = 10000; var result = []; for (var i = 0; i < N; i++) { result[i] = i * 2; }