Run results for: rest parameters vs arguments

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:138.0) Gecko/20100101 Firefox/138.0

Browser: Firefox 138

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

rest parameter

31K/s

arguments

22K/s

View exact numbers

Test name	Executions per second
✓ rest parameter	30,594 Ops/sec
arguments	21,696 Ops/sec

Script Preparation code:

function h1(tag, props) {
    props = Object.assign({}, props);
    let length = arguments.length;
    if (length > 3) {
        const children = [];
        while (length-- > 2) {
            children[length - 2] = arguments[length];
        }
        props.children = children;
    } else if (length === 3) {
        props.children = arguments[2];
    }
    return {
        tag,
        props
    };
}

function h2(tag, props, ...children) {
    props = Object.assign({}, props);
    if (children.length > 1) {
        props.children = children;
    } else if (children.length === 1) {
        props.children = children[0];
    }
    return {
        tag,
        props
    };
}

Tests:

arguments
const els = []; for (let i = 0; i < 1000; i++) { if (i % 3 === 0) { els.push(h1('div', {class: 'foo'}, i, i + 1, i + 2)); } else { els.push(h1('div', {class: 'foo'}, i)); } }
rest parameter
const els = []; for (let i = 0; i < 1000; i++) { if (i % 3 === 0) { els.push(h2('div', {class: 'foo'}, i, i + 1, i + 2)); } else { els.push(h2('div', {class: 'foo'}, i)); } }