HashMapExample.java

package com.examplehub.basics;

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

public class HashMapExample {
  public static void main(String[] args) {
    HashMap<String, String> hashMap = new HashMap<>();
    hashMap.put("Java", "Easy");
    hashMap.put("Python", "So easy");
    hashMap.put("C", "normal");

    /*
     * {Java=Easy, C=normal, Python=So easy}
     */
    System.out.println(hashMap);

    /*
     * So easy
     */
    System.out.println(hashMap.get("Python"));

    /*
     * Easy
     */
    System.out.println(hashMap.remove("Java"));

    /*
     * false
     */
    System.out.println(hashMap.remove("Python", "so easy"));

    /*
     * {C=normal, Python=So easy}
     */
    System.out.println(hashMap);

    /*
     * 2
     */
    System.out.println(hashMap.size());

    /*
     * C
     * Python
     */
    for (String key : hashMap.keySet()) {
      System.out.println(key);
    }

    /*
     * normal
     * So easy
     */
    for (String value : hashMap.values()) {
      System.out.println(value);
    }

    /*
     * C : normal
     * Python : So easy
     */
    for (Map.Entry<String, String> entry : hashMap.entrySet()) {
      System.out.println(entry.getKey() + " : " + entry.getValue());
    }
  }
}