js delete duplicates from array 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 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 3: 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 4: js delete duplicates from array

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

function removeDups(names) {
  let unique = {};
  names.forEach(function(i) {
    if(!unique[i]) {
      unique[i] = true;
    }
  });
  return Object.keys(unique);
}

removeDups(names); // // 'John', 'Paul', 'George', 'Ringo'

Example 5: 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;
}

Example 6: js delete duplicates from array

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

let x = (names) => names.filter((v,i) => names.indexOf(v) === i)
x(names); // 'John', 'Paul', 'George', 'Ringo'