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Java

Posted by Amrit Pandey
Amrit Pandey
17,595 Points

Declaring Instance of a class in other class! | JAVA

Hi I was wondering, what just happened in Hangman Game. In Prompter.java we have declared game instance which was created in Hangman.java. Alright so I am confused as to why it was necessary to declare game instance using Game as datatype. Both Prompter and Game had their instances already in Hangman.java.

Hangman.java ======>

public class Hangman{

   public static void main(String[] args){
      Game game = new Game("treehouse");
      Prompter prompter = new Prompter(game);

      boolean isHit = prompter.promptForGuess();

      if(isHit){
         System.out.println("We got a hit!");
      }else{
         System.out.println("Oops Missed!");
      }
   }
}

Prompter.java ======>

import java.util.Scanner;

class Prompter{

   private Game game;

   public Prompter(Game game){
      this.game = game;
   }

   public boolean promptForGuess(){
      Scanner scanner = new Scanner(System.in);
      System.out.print("Enter a letter: ");
      String guessInput = scanner.nextLine();
      char guess = guessInput.charAt(0);
      return game.applyGuess(guess);
   }
}

TL;DR I am not able to understand meaning of this line

private Game game;

in Prompter.java

1 Answer

Rohit Sai Teja Gadu
Rohit Sai Teja Gadu
619 Points
Rohit Sai Teja Gadu
Rohit Sai Teja Gadu
619 Points

Hey Amrit, we are using Game class in Prompter class, so we are declaring "private Game game" so that we can use game as an instance(object) of class Game in Prompter class (check Prompter class constructor: public Prompter(Game game))

Amrit Pandey
Amrit Pandey
17,595 Points

So as I know, to declare an instance of a class we do it by Game myGame = new Game(), The way we declare the instance of Game in Promppter is simply public Game game just like we do with the private variables!