How to Remove Duplicates from an Array of Objects in JavaScript? Last Updated : 19 Nov, 2024 Comments Improve Suggest changes Like Article Like Report Here are some effective methods to remove duplicates from an array of objects in JavaScript1. Using filter() and findIndex() Methods - Most UsedThe simplest way to remove duplicates is by using filter() and findIndex(). This method keeps the first occurrence of each object with a unique property (like id) and filters out duplicates. JavaScript const a = [ { a: '1', b: '2' }, { c: '2', d: '4' }, { c: '2', d: '4' }, { a: '1', b: '2' } ]; const uniqueArray = a.filter((o, index, arr) => arr.findIndex(item => JSON.stringify(item) === JSON.stringify(o)) === index ); console.log(uniqueArray); Output[ { a: '1', b: '2' }, { c: '2', d: '4' }]2. Using Set and JSON.stringify() Method for Complete DuplicatesIf you want to remove duplicates where all properties match, you can use Set and JSON.stringify() to convert objects to unique strings. This approach is useful for objects that need to be treated as identical only if every property is the same. JavaScript const a = [ { a: '1', b: '2' }, { c: '2', d: '4' }, { c: '2', d: '4' }, { a: '1', b: '2' } ]; const uniqueArray = Array.from(new Set(a.map(o => JSON.stringify(o)))).map(str => JSON.parse(str)); console.log(uniqueArray); Output[ { a: '1', b: '2' }, { c: '2', d: '4' }]3. Using filter() and includes() Methods with Unique Key ExtractionAnother approach is to use filter() and includes() by tracking unique keys, such as id, in an array. This method adds objects to the result only if their key hasn’t been added yet. JavaScript const a = [ { a: '1', b: '2' }, { c: '2', d: '4' }, { c: '2', d: '4' }, { a: '1', b: '2' } ]; const uniqueStrings = []; const uniqueArray = a.filter(o => { const s = JSON.stringify(o); if (!uniqueStrings.includes(s)) { uniqueStrings.push(s); return true; } return false; }); console.log(uniqueArray); Output[ { a: '1', b: '2' }, { c: '2', d: '4' }]4. Using Lodash’s _.uniqBy() MethodIf you using Lodash, the _.uniqBy() function simplifies removing duplicates. You can specify a unique property, like id, to keep only one instance of each object based on that key. JavaScript const _ = require('lodash'); const a = [ { a: '1', b: '2' }, { c: '2', d: '4' }, { c: '2', d: '4' }, { a: '1', b: '2' } ]; const uniqueArray = _.uniqWith(a, _.isEqual); console.log(uniqueArray); Output[ { a: '1', b: '2' }, { c: '2', d: '4' }]Importance of Removing Duplicates from an Array of ObjectsRemoving duplicates is essential forData Consistency: Ensuring accurate representation without repeated items.Performance Optimization: Reducing unnecessary data for faster processing.Data Presentation: Presenting unique items to avoid redundancy in user interfaces.Remove Duplicates from an Array of Objects in JavaScript Comment More infoAdvertise with us Next Article How to Remove Duplicates from an Array of Objects in JavaScript? sayantanm19 Follow Improve Article Tags : JavaScript Web Technologies javascript-array javascript-object JavaScript-DSA JavaScript-Questions +2 More Similar Reads How to Add Elements to a JavaScript Array? 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