by Sai gowtham

How to remove duplicate objects from an array in JavaScript

In this tutorial, we are going to learn about how to remove the duplicate objects from an array using JavaScript.

We are using es6 map and filter methods to remove the duplicate objects from an array, where object comparison is done by using the property

consider we have an array of objects with the id and name but the same id is repeating twice.

const arr = [
  { id: 1, name: "king" },
  { id: 2, name: "master" },
  { id: 3, name: "lisa" },
  { id: 4, name: "ion" },
  { id: 5, name: "jim" },
  { id: 6, name: "gowtham" },
  { id: 1, name: "jam" },
  { id: 1, name: "lol" },
  { id: 2, name: "kwick" },
  { id: 3, name: "april" },
  { id: 7, name: "sss" },
  { id: 8, name: "brace" },
  { id: 8, name: "peiter" },
  { id: 5, name: "hey" },
  { id: 6, name: "mkl" },
  { id: 9, name: "melast" },
  { id: 9, name: "imlast" },
  { id: 10, name: "glow" }
];

Here is my implementation to remove the duplicate objects from an array.


function getUnique(arr, comp) {

                    // store the comparison  values in array
   const unique =  arr.map(e => e[comp])

                  // store the indexes of the unique objects
                  .map((e, i, final) => final.indexOf(e) === i && i)

                  // eliminate the false indexes & return unique objects
                 .filter((e) => arr[e]).map(e => arr[e]);

   return unique;
}

console.log(getUnique(arr,'id'));

In the above code, we are using the chaining pattern where the output of a one map method will be the input of a other map method.

final array with unique objects

Codepen demo

Happy coding…

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