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

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.0 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 16

Operating system: iOS 16.0

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
var	17791690.0 Ops/sec
let	16235500.0 Ops/sec
const	15824300.0 Ops/sec
sloppy	2459752.0 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()