Run results for: Lodash keyBy vs JS Map

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser: Chrome 126

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Lodash keyBy (10k entries)

1K/s

JS Map (10k entries)

704/s

Lodash keyBy (100k entries)

72/s

JS Map (100k entries)

60/s

View exact numbers

Test name	Executions per second
✓ Lodash keyBy (10k entries)	1,324 Ops/sec
JS Map (10k entries)	704 Ops/sec
Lodash keyBy (100k entries)	72 Ops/sec
JS Map (100k entries)	60 Ops/sec

Script Preparation code:

window.data = [];
for (let i = 0; i < 10000; i++) {
    data.push({
        key: `key${i}`
    });
}

window.dataBig = [];
for (let i = 0; i < 100000; i++) {
    dataBig.push({
        key: `key${i}`
    });
}

Tests:

Lodash keyBy (10k entries)
const keyed = _.keyBy(data, 'key')
JS Map (10k entries)
const map = new Map(data.map((r, i) => [data.key, i]));
Lodash keyBy (100k entries)
const keyed = _.keyBy(dataBig, 'key')
JS Map (100k entries)
const map = new Map(dataBig.map((r, i) => [dataBig.key, i]));