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

public class Main {

	public static void main(String[] args) {

		/*      KEY   : VALUE

		 *   "red"    : "apple"
		 *   "yellow" : "banana"
		 *   "white"  : "radish"
		 *   "green"  : "apple"
		 * */

		Map<String, String> fruits = new HashMap<>();
		fruits.put("red", "apple");
		fruits.put("yellow", "banana");
		fruits.put("white", "radish");
		fruits.put("green", "apple");

//		fruits.containsKey("red");      // returns true, if key is found
//		fruits.containsValue("apple");  // returns true, if value is found
//		fruits.size();                  // returns the size of the MAP
//		fruits.remove("red");      // Deletes the Entry whose key is "red"
//		fruits.clear();

		System.out.println(fruits.get("red"));

		for (Map.Entry pairEntry: fruits.entrySet()) {
			System.out.println(pairEntry.getKey() + " : " + pairEntry.getValue());
		}
	}
}

/*
 *   Map: Interface
 *   HashMap: Class that implements interface Map
 *
 *       class HashMap implements Map {
 *           ...
 *       }
 *
 *   Map Properties:
 *       1. They contain values based on key
 *       2. They are not ordered
 *       3. "KEY" should be unique
 *       4. "VALUE" can be duplicate
 * */