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Question on inheritance

 
Greenhorn
Posts: 20
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Hello Everyone

I have a few quesions in the following code

class A
{
int i=20;
}

class B extends A
{
private int i=99;
}
class C extends B
{}

class test99
{
public static void main(String args[])
{
A a=new A();
B b=new B();
C c=new C();
System.out.println(a.i);
//System.out.println(b.i);
System.out.println(c.i);
}
}

1)Since B extends A,it already 'has' int i.So why is it allowed to redeclare it and make it private.
2)Why doesnt c.i compile?Though i is private in B,it has default access in A, and C is sub class of A indirectly.Why doesnt this compile?
 
Ranch Hand
Posts: 377
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Hi praneeth,

have a look at 8.3.3.2 Example: Hiding of Instance Variables in the Java Language Specification.
 
Ranch Hand
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Praneeth,

Pls read the notes on inheritance.
We have to learn the behavior as Rules. just apply the rules.


class A
{
int i=20;
}

class B extends A
{
private int i=99;
}
class C extends B
{}

class test99
{
public static void main(String args[])
{
A a=new A();
B b=new B();
C c=new C();
System.out.println(a.i);
//System.out.println(b.i);
System.out.println(c.i);
}
}

1)Since B extends A,it already 'has' int i.So why is it allowed to redeclare it and make it private.
2)Why doesnt c.i compile?Though i is private in B,it has default access in A, and C is sub class of A indirectly.Why doesnt this compile?
[/QB]




it is very simple.
1) redeclaration is allowed in inheritance, now B.i is different from A.i, Programmer can prevent a variable access in sub class by specifying it as private though it is declared in super class.
2) c.i is won't compile. because the immediate super class B is having private access to i, then its subclass cannot access it.


Thanks
Madhu
 
Ranch Hand
Posts: 102
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i am totally agree with the "madhu v pe". at first i also get same question what you get.. but after reading posted reply my question get clear...
 
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