Java-programs/LearnHashMap.java at main · tejaspundpal/Java-programs · GitHub

31 lines (28 loc) · 996 Bytes

import javax.swing.text.html.parser.Entity;

import java.util.*;

public class LearnHashMap

{

public static void main(String[] args) {

Map<String,Integer> numbers = new HashMap<>();

numbers.put("one",1);

numbers.put("five",5);

numbers.put("two",2);

numbers.put("three",3);

//numbers.put("two",22); ------> override the old value

//numbers.putIfAbsent("two",22);

System.out.println(numbers);

for(Map.Entry<String,Integer> e: numbers.entrySet()){

System.out.println(e);

}

// for(Map.Entry<String,Integer> e: numbers.entrySet()){

// System.out.println(e.getKey());

// System.out.println(e.getValue());

// }

for(String key: numbers.keySet()){

System.out.println(key);

}

System.out.println(numbers.containsKey("one"));

numbers.replace("one",1,11);

System.out.println(numbers);

}

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