Run results for: Shift loop vs unrolled

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; ONEPLUS A5010) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.120 Mobile Safari/537.36

Browser: Chrome Mobile 91

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
Shift loop	900.6 Ops/sec
Unrolled Loop	253.1 Ops/sec

Tests:

Shift loop

const arr = [];
const ARRAY_SIZE = 5000;
for (let i = 0; i < ARRAY_SIZE; i++) {
  arr.push(i);
}
while(arr.length) {
  let index = arr.shift();
  index++;
}

AخA
 
const arr = [];const ARRAY_SIZE = 5000;for (let i = 0; i < ARRAY_SIZE; i++) {  arr.push(i);}while(arr.length) {  let index = arr.shift();  index++;}

Unrolled Loop

arr = [];
const ARRAY_SIZE = 5000;
for (let i = 0; i < ARRAY_SIZE; i++) {
  arr.push(i);
}

const arrSize = arr.length;
for (let i = 0; i < arrSize; i++) {
  let index = arr[i];
  index++;
}
arr = [];

​x
 
arr = [];const ARRAY_SIZE = 5000;for (let i = 0; i < ARRAY_SIZE; i++) {  arr.push(i);}​const arrSize = arr.length;for (let i = 0; i < arrSize; i++) {  let index = arr[i];  index++;}arr = [];