javascript array duplicate remove 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: javascript filter array remove duplicates

// Using the Set constructor and the spread syntax:

arrayWithOnlyUniques = [...new Set(arrayWithDuplicates)]

Example 3: javascript remove duplicates from array

function toUniqueArray(a){
    var newArr = [];
    for (var i = 0; i < a.length; i++) {
        if (newArr.indexOf(a[i]) === -1) {
            newArr.push(a[i]);
        }
    }
  return newArr;
}
var colors = ["red","red","green","green","green"];
var colorsUnique=toUniqueArray(colors); // ["red","green"]

Example 4: how to remove duplicate values in array javascript

var car = ["Saab","Volvo","BMW","Saab","BMW",];
var cars = [...new Set(car)]
document.getElementById("demo").innerHTML = cars;

Example 5: 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 6: remove duplicate array es6

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