remove duplicate item from array javascript code example

Example 1: js delete duplicates from array

const names = ['John', 'Paul', 'George', 'Ringo', 'John'];

let unique = [...new Set(names)];
console.log(unique); // 'John', 'Paul', 'George', 'Ringo'

Example 2: how to remove duplicates in array in javascript

const numbers = [1 , 21, 21, 34 ,12 ,34 ,12];
const removeRepeatNumbers = array => [... new Set(array)]
removeRepeatNumbers(numbers) // [ 1, 21, 34, 12 ]

Example 3: javascript remove duplicates from array

var myArr = [1, 2, 2, 2, 3];
var mySet = new Set(myArr);
myArr = [...mySet];
console.log(myArr);
// 1, 2, 3

Example 4: remove duplicates array javascript

var data = [1, 2, 'Peter', 3, 3,'Peter', 2, 2, 1, 2, 3, 4, 4, 5, 4];
var unique = data.filter((v, i, a) => a.indexOf(v) === i);

Example 5: remove duplicate array es6

let a = [10,20,30,10,30];
let b = a.filter((item,index) => a.indexOf(item) === index);
console.log(b);

Example 6: javascript remove duplicate strings from array

//ES6
let uniqueArray = [...new Set(arrayWithDuplicates)];

//Alternative
function removeArrayDuplicates(arrayWithDuplicates) {
    let seen = {};
    let uniqueArray = [];
    let len = arrayWithDuplicates.length;
    let j = 0;
    for(let i = 0; i < len; i++) {
         let item = arrayWithDuplicates[i];
         if(seen[item] !== 1) {
               seen[item] = 1;
               uniqueArray[j++] = item;
         }
    }
    return uniqueArray;
}