Run results for: Unique item in Array of objects: reduce vs for loop

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36

Browser: Chrome 91

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Array Unique	588.1 Ops/sec
For Loop	965.9 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:

function getRandomInt(max) {
    return Math.floor(Math.random() * Math.floor(max));
}

var testArr = [];
for (var i = 0; i < 100000; i++) {
    testArr.push({
      val: String(getRandomInt(1000))
    });
}

Tests:

Array Unique
const { resultArray } = testArr.reduce((result, item) => { if(!result.resultMap[item.val]){ result.resultMap[item.val] = true; result.resultArray.push(item) } return result; }, {resultArray: [], resultMap: {}}); return resultArray;
For Loop
const resultArray = []; const resultMap = {}; for(let item of testArr) { if(!resultMap[item.val]){ resultMap[item.val] = true; resultArray.push(item) } } return resultArray;
Array Unique - v2
const resultObj = testArr.reduce((result, item) => { if(!result[item.val]){ result[item.val] = item; } return result; }, {}); const resultArray = Object.values(resultObj); return resultArray;
For Loop - v2
const resultObj = {}; for(let item of testArr) { if(!resultObj[item.val]){ resultObj[item.val] = item; } } const resultArray = Object.values(resultObj); return resultArray;

Run results for: Unique item in Array of objects: reduce vs for loop

Array Unique

For Loop

Array Unique - v2

For Loop - v2