Run results for: lodash/keyBy vs native reduce, large dataset

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36

Browser: Chrome 112

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
lodash/keyBy	15819.7 Ops/sec
keyBy with native reduce	16394.2 Ops/sec
keyBy with forEach	14509.5 Ops/sec
keyBy with for loop	16662.9 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' },
];


for(let i =0; i<1000; i++){
	data.push({
      name: `i-${i}`,
      value: i + (i*10) + (i*100),
      junk1: 'junk',
      junk2: 123,
      junk3: 'morejunk',
      junk4: 'evenmore',
      junk5: 345,
      junk6: 789,
      junk7: 'blah',
      junk8: 'baasdsadsadassdsadasdsa dsasdfdsfaascacf afaw',
      junk9: 'badadadadadadad',
      junk10: false,
      junk11: true,
      junk12: null
    })
}


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;
};

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);

Run results for: lodash/keyBy vs native reduce, large dataset

lodash/keyBy

keyBy with native reduce

keyBy with forEach

keyBy with for loop