Run results for: slice VS splice VS shift: who is the fastest to keep constant size

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_2_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/131.0.6778.154 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 131

Operating system: iOS 18.2.0

Device Platform: Mobile

Date tested: one year ago

Benchmark engine: Benchmark.js

shift

31.6M/s

splice

26.1M/s

slice

429/s

View exact numbers

Test name	Executions per second
✓ shift	31,603,498 Ops/sec
splice	26,074,274 Ops/sec
slice	429 Ops/sec

Script Preparation code:

var list = [];
for (var i = 0; i < 1000 * 1000; i++) {
  list.push(i);
}

Tests:

slice
list.push('slice'); list = list.slice(1);
splice
list.push('splice'); list.splice(0, 1);
shift
list.push('splice'); list.shift();

Run results for: slice VS splice VS shift: who is the fastest to keep constant size

100k list splice and shift win, they mutate list slice loose, it creates a copy of list 7.5x slower

slice

splice

shift