Untyped vs. typed JavaScript Arrays

typed.js

const { performance } = require('perf_hooks')

const start = performance.now()

const buffer = new ArrayBuffer(393216)
let uInt32View = new Uint32Array(buffer)

const length = uInt32View.length
for (let i = 0; i < length; i++) {
  uInt32View[i] = i
}

const end = performance.now()

console.log(uInt32View.length)
console.log(uInt32View[uInt32View.length - 1])
console.info(end - start) // ~1.569806999526918

untyped.js

const { performance } = require('perf_hooks')

const start = performance.now()

let untypedArray = []
for (let i = 0; i < 98304; i++) {
  untypedArray[i] = i
}

const end = performance.now()

console.log(untypedArray.length)
console.log(untypedArray[untypedArray.length - 1])
console.info(end - start) // ~2.792820000089705