Run results for: lodash/keyBy vs native reduce vs map

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser: Chrome 141

Operating system: Windows

Device Platform: Desktop

Date tested: 11 months ago

Benchmark engine: Benchmark.js

map

60.8M/s

keyBy with for loop

21.2M/s

lodash/keyBy

18.1M/s

keyBy with forEach

14.7M/s

keyBy with native reduce

14.3M/s

View exact numbers

Test name	Executions per second
✓ map	60,825,552 Ops/sec
keyBy with for loop	21,205,740 Ops/sec
lodash/keyBy	18,100,128 Ops/sec
keyBy with forEach	14,704,039 Ops/sec
keyBy with native reduce	14,343,515 Ops/sec

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var data = [
  { name: 'pi', value: 3.14 },
  { name: 'hundred', value: 100 },
  { name: 'truthy', value: true },
  { name: 'falsy', value: false },
  { name: 'estring', value: '2.71828' },
];

var keyBy = (array, fn) => {
  return array.reduce((acc, value) => {
    acc[fn(value)] = value;
    return acc;
  }, {});
};

var keyByForEach = (array, fn) => {
  var acc = {};
  _.forEach(array, (value) => {
    acc[fn(value)] = value;
  });
  return acc;
};

var keyByForLoop = (array, fn) => {
  var acc = {};
  for (let i = 0; i < array.length; i++) {
    acc[fn(array[i])] = array[i];
  }
  return acc;
};

var mapkey = (array, fn) => {
  return array.map(fn);
}

Tests:

lodash/keyBy
_.keyBy(data, (v) => v.name);
keyBy with native reduce
keyBy(data, (v) => v.name);
keyBy with forEach
keyByForEach(data, (v) => v.name);
keyBy with for loop
keyByForLoop(data, (v) => v.name);
map
mapkey(data, (v) => v.name);