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

32.4M/s

let

7.8M/s

const

5.6M/s

sloppy

2.0M/s

View exact numbers

Test name	Executions per second
✓ var	32,421,064 Ops/sec
let	7,839,956 Ops/sec
const	5,611,410 Ops/sec
sloppy	2,033,091 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()