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Java Class Q&A » parent class » variable 

1. Can parent and child class in Java have same instance variable?    stackoverflow.com

Consider these classes:

class Parent {
 int a;
}

class Child extends Parent {
 int a; // error?
}
Should the declaration of a in Child not give compilation error due to multiple declarations of int ...

2. Java: variable from parent class in child one isn't initialized and holds null    stackoverflow.com

Parent class(*ch.qos.logback.core.FileAppender*):

     ...

   protected String fileName = null;

   public FileAppender() {
      }

       ...

3. How to Access and Set variable in parent class    java-forums.org

Hi, I have 3 classes, A, B, and C. B extends A, and C extends B. Each class has a protected variable named x. Class A has a method to set x, and one to retrieve x, which I understand are inherited by both B and C. What I'm trying to do is also have a method in C that can ...

4. Can you use the super keyword when variables in parent class are private?    java-forums.org

If I have this code: public class A { int k = 10; } public class B extends A { public void m() { System.out.println(super.k); } public static void main(String[] arguments) { B b = new B(); b.m(); } } I get 10. If I make k private, then I can't access k and can use a get method: public class ...

5. Accessing variables in a parent class?    forums.oracle.com

No, an object has no way of knowing about the other object which created it. The fact that the other object might have had some subclassing relationship with it doesn't change that. If you want Object A to know about Object B, then Object A has to have a reference to Object B. There's no getting around that. Although I suspect ...

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