Run results for: Create an array with unique values - Javascript Array.reduce/Array.indexOf vs Lodash Uniq vs custom fn vs custom2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.5005.115 Safari/537.36

Browser: Chrome 102

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Javascript Array.reduce/Array.indexOf	59695.1 Ops/sec
object literal/res.push(arr[i]);	371876.7 Ops/sec
object literal/res.length	370664.2 Ops/sec

Script Preparation code:

var itemsCount = 1e2;
var items = Array.from({ length: itemsCount }, () => Math.floor(Math.random() * itemsCount));

AخA
 
var itemsCount = 1e2;var items = Array.from({ length: itemsCount }, () => Math.floor(Math.random() * itemsCount));

Tests:

Javascript Array.reduce/Array.indexOf
items.reduce((list, item) => list.indexOf(item) > -1 ? list : [...list, item], []);
items.reduce((list, item) => list.indexOf(item) > -1 ? list : [...list, item], []);

object literal/res.push(arr[i]);

function unique(arr) {
    var hash = {}, result = [];
    for ( var i = 0, l = arr.length; i < l; ++i ) {
        if ( !hash.hasOwnProperty(arr[i]) ) {
            hash[ arr[i] ] = true;
            result.push(arr[i]);
        }
    }
    return result;
}
unique(items)

 
function unique(arr) {    var hash = {}, result = [];    for ( var i = 0, l = arr.length; i < l; ++i ) {        if ( !hash.hasOwnProperty(arr[i]) ) {            hash[ arr[i] ] = true;            result.push(arr[i]);        }    }    return result;}unique(items)

object literal/res.length

function unique(arr) {
    var hash = {}, result = [];
    for ( var i = 0, l = arr.length; i < l; ++i ) {
        if ( !hash.hasOwnProperty(arr[i]) ) {
            hash[ arr[i] ] = true;
            result[result.length] = arr[i];
        }
    }
    return result;
}
unique(items)

 
function unique(arr) {    var hash = {}, result = [];    for ( var i = 0, l = arr.length; i < l; ++i ) {        if ( !hash.hasOwnProperty(arr[i]) ) {            hash[ arr[i] ] = true;            result[result.length] = arr[i];        }    }    return result;}unique(items)