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

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:138.0) Gecko/20100101 Firefox/138.0

Browser: Firefox 138

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

JS Map (10k entries)

2K/s

Lodash keyBy (10k entries)

1K/s

JS Map (100k entries)

64/s

Lodash keyBy (100k entries)

59/s

View exact numbers

Test name	Executions per second
✓ JS Map (10k entries)	2,407 Ops/sec
Lodash keyBy (10k entries)	1,375 Ops/sec
JS Map (100k entries)	64 Ops/sec
Lodash keyBy (100k entries)	59 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]); }