java maps

import java.util.*; public class Test { public static void main(String[] args) { Map<String, String> map = new HashMap<>(); map.put(“New York”, “city”); map.put(“Japan”, “country”); map.put(“London”, “country”); map.put(“Boston”, “city”); // update the value of “London” to “city” map.replace(“London”, “city”); System.out.println(map); } } Output: {New York=city, Japan=country, London=city, Boston=city} public class Test { public static void main(String[] args)…

Read More Java – Change the value of a key in a HashMap

public class Test { public static void main(String[] args) { Map<String, Integer> map = new HashMap<>(); map.put(“one”, 1); map.put(“two”, 2); map.put(“three”, 3); map.put(“four”, 4); // modify the key “two” map.remove(“two”); map.put(“twoUpdated”, 2); System.out.println(map); } } Output: {four=4, one=1, twoUpdated=2, three=3} public class Test { public static void main(String[] args) { Map<String, Integer> map = new…

Read More Java – Update the Key in a HashMap

class Test { public static void main(String[] args) { Map<Integer, String> map = new HashMap<>(); map.put(1, “Java”); map.put(7, “Python”); map.put(10, “Ruby”); map.put(3, “Kotlin”); for (Map.Entry<Integer, String> entry : map.entrySet()) { System.out.println(“Key = ” + entry.getKey() + “, Value = ” + entry.getValue()); } } } Output: Key = 1, Value = Java Key = 3,…

Read More Iterate over a Map in Java

HashMap<K, V> map = new HashMap<>(); Map<Integer, String> map = new HashMap<>(); class Test { public static void main(String[] args) { Map<Integer, String> map = new HashMap<>(); map.put(1, “Java”); map.put(7, “Python”); map.put(10, “Ruby”); map.put(3, “Kotlin”); System.out.println(map); } } Output: {1=Java, 3=Kotlin, 7=Python, 10=Ruby} class Test { public static void main(String[] args) { Map<Integer, String> map…

Read More Map in Java