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

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.3 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 16

Operating system: iOS 16.3

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
var	21199620.0 Ops/sec
let	19926610.0 Ops/sec
const	19725880.0 Ops/sec
sloppy	2724759.0 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()