benchmark of forward vs backward for loop with node.js

forward_vs_backward_for_loop.js

'use strict'

const size = 10000000

let arr = new Array(size)

for (let i = 0; i < size; i++) {
	arr[i] = i + ''
}

console.time(`for (let i = 0; i < ${size}; i++) `)
for (let i = 0; i < size; i++) {
	if (arr[i] > size) console.log(1)
}
console.timeEnd(`for (let i = 0; i < ${size}; i++) `)

console.time(`for (let i = ${size}; i >= 0; i--)`)
for (let i = size; i >= 0; i--) {	
	if (arr[i] > size) console.log(1)
}
console.timeEnd(`for (let i = ${size}; i >= 0; i--)`)

on my machine:

for (let i = 0; i < 10000000; i++) : 1062.352ms
for (let i = 10000000; i >= 0; i--): 729.478ms