3
06/11/2024 7:38 дп
Топик стартер
How can I make a Map in Java (with Keys and Values)?
Can you please give me some examples of Map's usage in Java?
Спасибо!
1 Ответ
2
06/11/2024 7:38 дп
- To add an item in a map use the method: .put() and inside the brackets put your Key and Value (line 8);
- To get a Key and a Value you are using the method: .get() and inside the brackets put the Key (NOT the Value - otherwise a null will be shown in the console) (line 15)
- To remove Key + Value use the method: .remove() and inside the brackets put the Key (line 18)
See the code and read the comments to clear things up:
import java.util.HashMap; import java.util.Map; public class HashMapCode { public static void main(String[] args) { Map<String, String> map = new HashMap<>();//CREATING A MAP map.put("Germany", "Berlin");//ADDING AN ITEM TO A MAP<Key, Value> map.put("Spain", "Madrid"); map.put("Greece", "Athens"); map.put("Turkey", "Ankara"); System.out.println(map); String capital = map.get("Germany");//GETTING THE Value OF THE Key: Germany System.out.println("The capital of Germany is: " + capital); map.remove("Spain");//REMOVING A Key+Value System.out.println(map); } }
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