How to remove duplicate elements from array JavaScript

by Sai gowtham  1 Min read

In this tutorial, we will learn about how to remove duplicate elements from an array.

First way

We are using JavaScript new Set Object to store the unique elements from the array.

const numbers = [2,3,4,4,2,3,3,4,4,5,5,6,6,7,5,32];

console.log([...new Set(numbers)]);

// [2, 3, 4, 5, 6, 7, 32]

Second way

Array.map() method.

const jobs = ['Web Developer','Marketing Manager','Project   Manager','Web Developer'];

function getUnique(arr){

  const final = [];

  arr.map((e,i)=> !final.includes(e) && final.push(e) )

  return final
}

console.log(getUnique(jobs))

//["Web Developer", "Marketing Manager", "Project Manager"]

In the above code, on each iteration, we check if an element is not present in the final array then we are pushing that element to the final array.

Third way

const jobs = ['Web Developer','Marketing Manager','Project Manager','Web Developer']

function getUnique(arr){

 return arr.filter((e,i)=> arr.indexOf(e) >= i)
}

console.log(getUnique(jobs))

//["Web Developer", "Marketing Manager", "Project Manager"]

On each iteration, we are using the Array.indexOf method to get the index of that element. if the returned index is greater than the current index then we will add that element to a new array and return it.

Happy coding…