Run results for: Access Object Property vs Global Let vs Private Let

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.2 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.2

Device Platform: Mobile

Date tested: one year ago

Object

63K/s

Private Let

61K/s

Global Let

60K/s

View exact numbers

Test name	Executions per second
✓ Object	62,787 Ops/sec
Private Let	60,598 Ops/sec
Global Let	60,405 Ops/sec

Script Preparation code:

const array = Array(1000);
for (let arr of array)
    arr = Math.random(10);

const obj = {
    a: 0,
    b: 0,
}
var ofunc = () => {
    for (let arr of array) {
        obj.a += arr;
        obj.b += obj.a + arr;
    }
}

let ga = 0;
let gb = 0;
var gfunc = () => {
    for (let arr of array) {
        ga += arr;
        gb += ga + arr;
    }
}

var pfunc = (() => {
    let a = 0;
    let b = 0;
    return () => {
        for (let arr of array) {
            a += arr;
            b += a + arr;
        }
    }
})();

Tests:

Object
ofunc();
Global Let
gfunc();
Private Let
pfunc();