find the frequency of elements in a java array

Question

I have an int array:

{1,2,4,2,3,5,6,4,3}

How can I find frequencies of array elements like 1=1,2=2,3=2,4=4... I need a class w

Answer 1

You can also try below code,

    Map map = new HashMap<>();
    int arr[] = new int[]{2, 2, 3, 3, 4, 5, 6, 7, 9, 9, 0, 4, 2};

    for (int i = 0; i < arr.length; i++) {
        Integer count = map.getOrDefault(arr[i], 0);
        map.put(arr[i], count + 1);
    }

    //Print the map to see the occurrence
    map.forEach((key, value) -> {
        System.out.println(key + " -> " + value);
    });