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/605.1.15 (KHTML, like Gecko) Version/16.2 Safari/605.1.15

Browser: Safari 16

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
var	13854940.0 Ops/sec
let	13654250.0 Ops/sec
const	11782840.0 Ops/sec
sloppy	1615583.0 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()