Run results for: var only vs let + const

Run details:

User agent: Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36

Browser: Chrome 65

Operating system: Fedora

Device Platform: Desktop

Date tested: 6 years ago

Test name	Executions per second
var only	327.7 Ops/sec
let + const	320.1 Ops/sec

Script Preparation code:

var array = Array.from(Array(10000).keys());

Tests:

var only
for(var i = 1; i < array.length; i++) { var prev = array[i-1]; var curr = array[i]; array[i-1] = prev + curr; }
let + const
for(let i = 1; i < array.length; i++) { const prev = array[i-1]; const curr = array[i]; array[i-1] = prev + curr; }