variables cannot be overridden ?

[Vijay Pawar]

  
class A
{
public String xyz = "hello";
public void print(){
System.out.println(xyz);
}
}
 
class B extends A
{
public  String xyz = "world";


}
 
public class Test
{
public static void main(String[] str){
B b = new B();
b.print();
}
}

This prints "hello" and does not print "world"

But we put the print() method in class B then it prints "world"

 
class A
{
public String xyz = "hello";

}
 
class B extends A
{
public  String xyz = "world";
public void print(){
System.out.println(xyz);
}
 

}
 
public class Test
{
public static void main(String[] str){
B b = new B();
b.print();
}
}
 

Can someone explain this behaviour

[Swamy Nathan]

Vraiables cannot be overriden but they can be hidden by another variable which has the same name and even a different type. The hider and hidden can even differ on whether it uses the static modifier.

in the overridden method the hidden variable is not visible.
What is visible is the hider vriable and that is what gets used in the derived class.

[Peter den Haan]

Correct: variables, like static methods, cannot be overridden. They can only be obscured. The reference to "xyz" is resolved to the instance variable in class A when the class is compiled. That class B declares a variable of the same name is irrelevant.

Compare this with methods; a reference to the "print()" method in class A would only be resolved when the code is executed; if you have an object of class B, it would call "print()" in class B if it has been overridden there.

- Peter

[Corey McGlone]

Vijay,

Welcome to Javaranch

We'd like you to read the Javaranch Naming Policy and change your publicly displayed name (change it here) to comply with our unique rule. Note that, in order to comply with our naming convention, you must supply both a first AND last name. The names need not be real, but they must not be obviously fictitious. Thank you.
[ June 03, 2004: Message edited by: Corey McGlone ]