Run results for: map vs array accessor

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 26_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Brave/1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 26

Operating system: iOS 26.3

Device Platform: Mobile

Date tested: 6 months ago

Benchmark engine: Benchmark.js

Accessing random index in array

104K/s

Accessing random index in map

91K/s

View exact numbers

Test name	Executions per second
✓ Accessing random index in array	104,364 Ops/sec
Accessing random index in map	91,467 Ops/sec

Script Preparation code:

window.ITEMS_ARRAY = Array(1000).fill(null).map((item, index) => {
    return {
        id: index,
        name: '10 Portable DVD player',
        description: 'diam neque vestibulum eget vulputate',
        price: {
            value: 66.04,
            currency: 'CNY'
        },
        status: 'Stocked on demand',
        statusColor: 'informative',
        date: new Date(),
        verified: true
    };
});

window.ITEMS_MAP = new Map(ITEMS_ARRAY.map((item, index) => [index, item]));

window.initialIndex = Math.floor(Math.random() * 500);

window.indexes = new Array(500).fill(null).map((item, index) => window.initialIndex + index);

Tests:

Accessing random index in array
window.indexes.forEach((index) => { const smt = window.ITEMS_ARRAY[index]; });
Accessing random index in map
window.indexes.forEach((index) => { const smt = window.ITEMS_MAP.get(index); });