Run results for: Lodash keyBy vs JS Map (with small and large size)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser: Chrome 133

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Lodash keyBy (10k entries)

3K/s

JS Map (10k entries)

2K/s

Lodash keyBy (100k entries)

151/s

JS Map (100k entries)

116/s

View exact numbers

Test name	Executions per second
✓ Lodash keyBy (10k entries)	2,642 Ops/sec
JS Map (10k entries)	2,184 Ops/sec
Lodash keyBy (100k entries)	151 Ops/sec
JS Map (100k entries)	116 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, v => v.key)
JS Map (10k entries)
const map = new Map(); for (let i = 0; i < data.length; i++) { map.set(data[i].key, data[i]); }
Lodash keyBy (100k entries)
const keyed = _.keyBy(dataBig, v => v.key)
JS Map (100k entries)
const map = new Map(); for (let i = 0; i < dataBig.length; i++) { map.set(dataBig[i].key, dataBig[i]); }