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Start your free trialLucas Caldeira
977 Pointswhat does these lines do ? private Game mGame; public Prompter(Game game) { mGame = game;
public class Prompter { private Game mGame;
public Prompter(Game game) { mGame = game;}
2 Answers
Christopher Augg
21,223 PointsHello Lucas. Let's see if we can understand these lines better.
public class Prompter { // Start class definition. Make public and name it Prompter
/* This is a member field (variable) even though it is using an object type to reference a Game object. It is important to
* remember that in Java, no variable can ever hold an object. A variable can only hold a reference to an object. This means
* that mGame can hold the memory address of an instantiated Game object. This is different than the primitive data
* types like int, double, etc. Those can hold actual values (i.e private int numCars = 3; ).
*/
private Game mGame;
/* This is the constructor for the Prompter class that is called upon instantiation of a prompter obj. Notice that it is passing a
* reference to a Game object named game. Again, this is a reference only. Therefore, mGame gets assigned the memory
* address of game. This is not a good practice because it violates encapsulation. mGame was set as a private field, but since
* the memory address was passed by reference to the constructor, any changes to the game object outside the Prompter
* object will still change for mGame inside it as well because both variables are essentially referencing the same object.
*/
public Prompter(Game game) {
mGame = game;
}
} // End class definition
I hope that helps
Yongshuo Wang
5,500 PointsThis is line is declare a variable with type Game, in the constructor set the value from this variable.
Lucas Caldeira
977 PointsLucas Caldeira
977 Pointsmakes sense now thank you !