array filter unique numbers code example

Example 1: 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] )); //[]

Example 2: unique numbers in array

import java.util.ArrayList;

public class UniqueNumbersInArray {

    public static void main(String[] args) {


    int arr[] = { 4,5,5,4,5,6,5,8,4,7};

        ArrayList<Integer> uniqueArr = new ArrayList<Integer>();
        for (int i = 0; i < arr.length; i++) {

            int k = 0;
            if (!uniqueArr.contains(arr[i])){
                uniqueArr.add(arr[i]);
                k++;

                for (int j = i; j < args.length ; j++) {
                    if (arr[i]==arr[j]){
                        k++;
                    }
                }

                System.out.println(arr[i]);
                System.out.println(k);
            }

        }
    }
}