Run results for: const vs let vs var vs sloppy - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser: Chrome 120

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

var

52.1M/s

const

17.9M/s

let

17.8M/s

sloppy

4.3M/s

View exact numbers

Test name	Executions per second
✓ var	52,069,676 Ops/sec
const	17,859,804 Ops/sec
let	17,823,552 Ops/sec
sloppy	4,261,420 Ops/sec

Tests:

var
var g = { e: [] } g.o = function(x) { g.e.push(...[1,2,3]) } g.o()
let
let g = { e: [] } g.o = function(x) { g.e.push(...[1,2,3]) } g.o()
const
const g = { e: [] } g.o = function(x) { g.e.push(...[1,2,3]) } g.o()
sloppy
g = { e: [] } g.o = function(x) { g.e.push(...[1,2,3]) } g.o()