Method Overriding - Seriously confused :-(

Dear All,

I have two account classes say A and B. B extends A. I am trying to re-write a method in B that is also in A but I would like to expand on this method greatly. The problem is that my coursebooks tell me to do this:

Code:

---


public void credit(double money);
{
super.credit();
//and then expand on the method here

---

The credit method in A is written the same public void credit(double money);

When I try and compile the code - I get the error:

credit(double) in A cannot be applied to (). I then try and change the code to:

Code:

---


public void credit(double money);
{
super.credit(double money)
//and then expand on the method here

---

I then get the error message: .class expected.

All I can say is AAAAAAAH!

Any help would be gratefully received.

Cheers - FMJ.

Code:

---

public void credit(double money) {
    ...
}

public void credit(double money) {
    super.credit(25.00);  // any double value argument is okay
    //and then expand on the method here

---

or, you can just do

Code:

---

public void credit(double money) {
    // do what you like...

---

Watch the semicolons. They should appear at the end of statements. They should not appear in the middle of method definitions.

Compiler messages can be confusing to begin with. A SSCCE will help clarify things if you post the exact and entire compiler message you can't understand along with an indication of which lines in your code it is referring to.

How many times - go through the tutorials.

Calling the super method is exactly the same as calling any method. You don't put a type in the arguments for a method call.

here is a little code example. pay attention to the comments in the code.
As you have it now calling super.credit(money) wont work unless you have something similar to my method at (1)

Code:

---

public class B {
        public void credit(){
                //do stuff in here
        }
       
        //(1)
        public void credit(double money){
                //overloaded methods(?) is where you have multiple methods with the same name and different parameters
        }
}

class A extends B{
        public void credit(double money){
                //this is accepted
                super.credit(); 

                //this isn't. In order to override the method
                //you have to have a method with those same parameters in your parent method.(1)
                //This method however won't be of too much use unless B.credit() is changed from
                //a void type to a double type.
                super.credit(money);
        }
}

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