method overloading

[David]

Hi guys,
I have two classes "Mother" and "Daughter".
Mother is an abstract class with a public method "foo()" implemented

"Daughter" extends Mother and implements a public method "foo()"
I want the foo() method from Daughter to perform some calculations then
call the implementation from "foo()" in the class Mother.

Is this possible, if yes, how please? I've tried it, but i've ended in an
infinite recursive call. Here's the dumb code:

//------------------------
abstract class Mother {
protected int x;
public void foo() {
System.out.println("x: " + x);
}
}

class Daughter extends Mother {
public void foo() {
x = 3;
((Daughter) this).foo();
}
}

public class Test {
public static void main(String[] args) {
Daughter d = new Daughter();
d.foo();
}
}
//------------------------

Fanxs for your help.

_
David Hitillambeau

 

[Christophe Vanfleteren]

Hi guys,
I have two classes "Mother" and "Daughter".
Mother is an abstract class with a public method "foo()" implemented

"Daughter" extends Mother and implements a public method "foo()"
I want the foo() method from Daughter to perform some calculations then
call the implementation from "foo()" in the class Mother.

Is this possible, if yes, how please? I've tried it, but i've ended in an
infinite recursive call. Here's the dumb code:

//------------------------
abstract class Mother {
protected int x;
public void foo() {
System.out.println("x: " + x);
}
}

class Daughter extends Mother {
public void foo() {
x = 3;
((Daughter) this).foo();
}
}

public class Test {
public static void main(String[] args) {
Daughter d = new Daughter();
d.foo();
}
}

You need to learn about the "super" keyword.
It can be used in 2 ways:

- to call a method in the superclass, which is what you need:
So in Daughter, you need to call Mother's foo like this:

public void foo() {
//do stuff
//call super classes foo method
super.foo();
}

- to call a constructor of the superclass:

public Daughter() {
super("I pass this to the Mother constructor");
}

 

[Christophe Vanfleteren]

Hi guys,
I have two classes "Mother" and "Daughter".
Mother is an abstract class with a public method "foo()" implemented

"Daughter" extends Mother and implements a public method "foo()"
I want the foo() method from Daughter to perform some calculations then
call the implementation from "foo()" in the class Mother.

Is this possible, if yes, how please? I've tried it, but i've ended in an
infinite recursive call. Here's the dumb code:

<snip code>

One more thing:

It's better to ask the newbie kind of questions in c.l.j.help instead.

 

[Roedy Green]

I have two classes "Mother" and "Daughter".
Mother is an abstract class with a public method "foo()" implemented

"Daughter" extends Mother and implements a public method "foo()"
I want the foo() method from Daughter to perform some calculations then
call the implementation from "foo()" in the class Mother.

see http://mindprod.com/jgloss/gotchas.html and search for the word
"recipe". It will explain the various types of overloading and
shadowing with a large example.

 

[David]

Thank you for your kind responses and i apologize for being
off-topic.

_
David Hitillambeau