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/109.0.0.0 Safari/537.36

Browser: Chrome 109

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
var	9920351.0 Ops/sec
let	10670310.0 Ops/sec
const	10038850.0 Ops/sec
sloppy	3166540.0 Ops/sec

Website performance monitoring

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()