package org.kodejava.basic;

import java.util.HashMap;
import java.util.Map;

public class NumberOccurrenceInArray {
    public static void main(String[] args) {
        int[] numbers = new int[]{1, 8, 3, 4, 3, 2, 5, 7, 3, 1, 4, 5, 6, 4, 3};

        Map<Integer, Integer> map = new HashMap<>();
        for (int key : numbers) {
            if (map.containsKey(key)) {
                int occurrence = map.get(key);
                occurrence++;
                map.put(key, occurrence);
            } else {
                map.put(key, 1);
            }
        }

        for (Integer key : map.keySet()) {
            int occurrence = map.get(key);
            System.out.println(key + " occur " + occurrence + " time(s).");
        }
    }
}

The result are:

1 occur 2 time(s).
2 occur 1 time(s).
3 occur 4 time(s).
4 occur 3 time(s).
5 occur 2 time(s).
6 occur 1 time(s).
7 occur 1 time(s).
8 occur 1 time(s).

• Author
• Recent Posts

Wayan

Founder at Kode Java

A programmer, runner and recreational diver, lives on the island of Bali, Indonesia. Programming in Java, Spring Framework, Hibernate / JPA, MySQL. To support me working on this project, buy me a cup of coffee, every little bit helps. Thank you.

Latest posts by Wayan (see all)

• How do I get number of each day for a certain month in Java? - September 8, 2024
• How do I get operating system process information using ProcessHandle? - July 22, 2024
• How do I sum a BigDecimal property of a list of objects using Java Stream API? - July 22, 2024