Questions and Exercises: Creating Classes - Java Tutorial 5.0 英文版

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Trail: Learning the Java Language
Lesson: Classes and Inheritance

Questions and Exercises: Creating Classes

Questions

1. Consider the following class:
public class IdentifyMyParts {
    public static int x = 7; 
    public int y = 3; 
}
a. How many class variables does the IdentifyMyParts class contain? What are their names?
b. How many instance variables does the IdentifyMyParts class contain? What are their names?
c. What is the output from the following code:
IdentifyMyParts a = new IdentifyMyParts();
IdentifyMyParts b = new IdentifyMyParts();
a.y = 5;
b.y = 6;
a.x = 1;
b.x = 2;
System.out.println("a.y = " + a.y);
System.out.println("b.y = " + b.y);
System.out.println("a.x = " + a.x);
System.out.println("b.x = " + b.x);

Exercises

1. Write a class whose instances represent a single playing card from a deck of cards. Playing cards have two distinguishing properites: rank and suit. Be sure to keep your solution as you will be asked to rewrite it in Enumerated Types.

2. Write a class whose instances represent full a deck of cards. You should also keep this solution.

3. Write a small program to test your deck and card classes. The program can be as simple as creating a deck of cards and displaying its cards.

Check your answers.

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