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 17_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.4.1

Device Platform: Mobile

Date tested: 2 years ago

Benchmark engine: Benchmark.js

shift

12.4M/s

splice

11.6M/s

slice

555/s

View exact numbers

Test name	Executions per second
✓ shift	12,373,522 Ops/sec
splice	11,627,072 Ops/sec
slice	555 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