Benchmark: Methods to remove duplicates object with a key from array

Script Preparation code:

var array = [];
for (let i = 0; i < 100000; i++) {
    array.push({
        id: Math.floor((Math.random() * 10) + 1),
        someOtherKey: "someOtherValue"
    });
}

Tests:

Using a Set
function removeDuplicates(items) { const seenIds = new Set(); const result = []; for (const item of items) { if (!seenIds.has(item.id)) { seenIds.add(item.id); result.push(item); } } return result; } removeDuplicates(array)
Using filter and findIndex
array.filter((item, index, array) => array.findIndex(i => i.id === item.id) === index );
Using reduce
array.reduce((acc, currentItem) => { const isDuplicate = acc.some(item => item.id === currentItem.id); if (!isDuplicate) { acc.push(currentItem); } return acc; }, []);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using a Set
Using filter and findIndex
Using reduce

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Windows

View result in a separate tab

Test name	Executions per second
Using a Set	801.4 Ops/sec
Using filter and findIndex	428.6 Ops/sec
Using reduce	450.6 Ops/sec

Methods to remove duplicates object with a key from array (version: 0)

Comparing performance of: Using a Set vs Using filter and findIndex vs Using reduce

Created: one month ago by: Guest

Jump to the latest result

Using a Set

Using filter and findIndex

Using reduce

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A