What is the difference in the accessibility of the following variables in Java?
public class Joe {
public int a;
protected int b;
...
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Why we are not able to override a instance variable of a super class in subclass?
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Say I have 3 classes like so:
class A {}
class B extends A {}
class C extends A {}
Would it then be possible to determine whether a particular object was an instance of ... |
As per java, instance method resolution is based on runtime types of the arguments.
But while resolving instance variable it uses different approach as shown below. ... |
Why are Instance variables of a superclass not overidden in Inheritance ?
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In java, I might have an object a with a bunch of properties like getColor. I then might make a second object b (possibly of the same class) that behaves ... |
The story goes like this:
I have an abstract class called Algorithms and a lot of classes that extend it. Some of them have parameters to tune. Some have none, and some ... |
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If I have objects such as:
Teacher extends Person
Student extends Person
Then, I have a function in a service that returns a List/Array, etc. of Persons, but some items on the list may ... |
Why do we assign an instance to an instance of upper class? What are the reasons to do it?
For ex. why we use this code below?
List lst = new LinkedList();
It ... |
for example:
public class MyParentClass
{
static MyParentClass AStaticMethod()
{
//get a new childclass instace here
//modify this instance
return(ChildClassInstance);
}
}
public ...
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Ttaking the following code, (source):
class Parent {
Integer a = 1;
static Integer b = 2;
}
class Child extends Parent ...
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I have 2 classes. Let's call them class A and class B. Class A contains a method that executes some action. Class B overrides this method with its ... |
I understood that this is a reference to the currently executing object. If that is the case can you explain the behaviour of the following code?
public class Inherit {
...
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What is the best use of Inheritance, other than it will reduce redundant code!
Let us take an example
Class A:Base Class
Class B:Sub Class
and Class C.
CLASS A
^
...
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I would like to do something like this:
Class A
Class B extends A
Class C extends A
B b = new B();
C c = new C();
b->setField("foo");
c->getField; //return "foo"
Is it somehow possible to ... |
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Hello Varuna, as always it depends on what you're planning to do. In very rare cases you will make the variables in the super class protected instead of private and let overriding classes use them directly. If you allow access through getters and setters, your overriding classes can use these methods. Alternatively, you could implement all state and behavior regarding those ... |
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Hello, I am working on a networked game where I have (amongst others ) a Player and a GameHost class. The GameHost extends the Player class. Now when the function Player.startnewgame() is done I want the player to become a Gamehost instance. I seem to have lost the insight in how this works. I can create a new GameHost() but that ... |
I am using the Sybex SCJP book to study for the 1.5 exam. Last night I did one of their mock exams on the CD and got a question wrong because, so the answer said, you "cannot access protected superclass data of a different instance". The specific context was a class a.X extends b.Y, and b.Y has a protected instance variable ... |
Given the following 2 classes (Dog.java extends Animal.java), please help me with the 2 questions listed below them. package pkga; public class Animal { protected int i = 1; } package pkgb; import pkga.Animal; public class Dog extends Animal { public int fromAnimal = i; System.out.println("1-protected Animal instance variable i = " + i); public void testIt() { System.out.println("2-protected Animal instance ... |
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