Benchmark: Map vs filter for unique properties in object

Script Preparation code:

const uniqueItems = {};

const arr = [{
        place: "here",
        name: "x",
        other: "other stuff1"
    },
    {
        place: "there",
        name: "x",
        other: "other stuff2"
    },
    {
        place: "here",
        name: "y",
        other: "other stuff4"
    },
    {
        place: "here",
        name: "z",
        other: "other stuff5"
    }
]

function getUniqueListByFilter() {
    return arr.filter((element) => {
        if (uniqueItems[element.place]) {
            return false;
        }

        uniqueItems[element.place] = true;

        return true;
    });
}

function getUniqueListByMap() {
    return [...new Map(arr.map(item => [item.place, item])).values()]
}

Tests:

use Map
const arr1 = getUniqueListByMap()
use Filter
const arr2 = getUniqueListByFilter()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
use Map
use Filter

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 25 days ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 121 on Android

View result in a separate tab

Test name	Executions per second
use Map	1563120.0 Ops/sec
use Filter	4669772.0 Ops/sec

Map vs filter for unique properties in object (version: 0)

Comparing performance of: use Map vs use Filter

Created: 26 days ago by: Guest

Jump to the latest result

use Map

use Filter

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A