JAVASCRIPT

javascript array unique values

var arr = [55, 44, 65,1,2,3,3,34,5];
var unique = [...new Set(arr)]

//just  var unique = new Set(arr) wont be an array

array unique values javascript

const myArray = ['a', 1, 'a', 2, '1'];
const unique = [...new Set(myArray)]; // ['a', 1, 2, '1']

javascript filter unique

function onlyUnique(value, index, self) {
  return self.indexOf(value) === index;
}

// usage example:
var a = ['a', 1, 'a', 2, '1'];
var unique = a.filter(onlyUnique);

console.log(unique); // ['a', 1, 2, '1']
 Run code snippet

get unique array javascript

// one liner solution to get a unique array by object id
[{_id: 10},{_id: 20}, {_id: 20}].filter((item, i, ar) => ar.findIndex(each => each._id === item._id) === i)

javascript remove uniques from array

function getNotUnique(array) {
    var map = new Map();
    array.forEach(a => map.set(a, (map.get(a) || 0) + 1));
    return array.filter(a => map.get(a) > 1);
}

console.log(getNotUnique([1, 2, 2, 4, 4])); //[2, 2, 4, 4]
console.log(getNotUnique([1, 2, 3] )); //[]

javascript unique array

const mySet = new Set([1,2])
const additionalSet = [5,2,6]
mySet = new Set([...mySet, ...additionalSet]) // {1,2,5,6}
array = [...new Set([...mySet, ...additionalSet])] // [1,2,5,6]