For, ForEach ForOf Benchmark

benchmark_tests.js

"use strict";
 
var Benchmark = require('benchmark'); // Using https://benchmarkjs.com

const dogs = Array(1000000).fill("Doggy"); // One million of items
 
var suite = new Benchmark.Suite;

suite.add('for#test', function() {
    for(let i = 0; i < dogs.lenght; i++){ 
        return dog[i]
    }
})
.add('for_caching#test', function() {
    const size = dogs.lenght;
    for(let i = 0; i < size; i++){ 
        return dog[i]
    }
})
.add('forEach#test', function() {
    dogs.forEach(function(dog, i){ 
        return dog;
    });
})
.add('forof#test', function() {
    for(const dog of dogs.entries()){ 
        return dog;
    }
})
.on('cycle', function(event) {
  console.log(String(event.target));
})
.on('complete', function() {
  console.log('Fastest is ' + this.filter('fastest').map('name'));
}) 

suite.run({ 'async': true });

Fastest

Fastest is for_caching#test

for#test

for#test x 55,659,660 ops/sec ±2.94% (78 runs sampled)

for_caching#test

for_caching#test x 56,174,776 ops/sec ±3.19% (79 runs sampled)

forEach#test

forEach#test x 7,783,568 ops/sec ±4.54% (76 runs sampled)

forof#test

forof#test x 5,088,843 ops/sec ±4.21% (79 runs sampled)