Run results for: slice vs moving array vs reduce

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:125.0) Gecko/20100101 Firefox/125.0

Browser: Firefox 125

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

reduce

7.2M/s

moving array

203K/s

slice

196K/s

View exact numbers

Script Preparation code:

var arr = [];
for (var i = 0; i < 100; i++) {
  arr.push(i);
}

Tests:

moving array
var range = []; for (var i = 0; i < arr.length; i++) { range.push(arr[i]); if (range.length > 9) { range.splice(0, 1); } if (i > 8) {var avg = range.reduce(function(accu, next){ return accu + next ;}) / 9;} }
slice
for (var i = 0; i < arr.length; i++) { if (i < 9) continue; var range = arr.slice(i, i + 9); var avg = range.reduce(function(accu, next){ return accu + next ;}) / 9; }
reduce
var sum = 0; for (var i = 0; i < arr.length; i++) { sum += arr[i]; if (i > 8) { sum -= arr[i - 9]; } if (i > 8) {var avg = sum / 9;} }