missing return value error

[Daniel Brackett]

Hi I am trying to return the value SavingsAcc in this coding exercise. I want to do this so that I can put together multiple methods in a single line. What do I need to do to fix it?

Here is the code;

public class SavingsAcc2
{
 private double balance;
 private double interest;


 public SavingsAcc2()
 {
 balance = 0.0;
 interest = 6.17;
 }

 public SavingsAcc2(double initBalance, double interested)
 {
 balance = initBalance;
 interest = interested;
 
 }

 public SavingsAcc2 deposit(double amount)
 {
 balance = balance + amount;
 return;
 }

 public SavingsAcc2 withdraw(double amount)
 {
 balance = balance - amount;
 return;
 }

 public SavingsAcc2 addInterest(double interest)
 {
 balance = balance * (interest / 100) + balance;
 return;
 }

 public double getBalance()
 {
 return balance;
 }
}

here is the error:



SavingsAcc2.java:29: missing return value
return;
^
SavingsAcc2.java:35: missing return value
return;
^
SavingsAcc2.java:41: missing return value
return;
^
3 errors


I am doing all of this from the command line I plan on using eclipse or DR java soon but I just don't know them yet.

[Brian Burress]

The method declarations such as "public SavingsAcc2 addInterest(double interest)" indicate a type of "SavingsAcc2" is expected to be returned. The return statement is not returning anything.

Not sure what the intent is. If you do not want anything returned, you can delcare void as the return type "public void addInterest(double interest)". Otherwise, you'll need to return an instance of SavingsAcc2 as it is currently coded.

[Greg Brannon]

The reason for the error is because your methods:

 public SavingsAcc2 deposit(double amount)
 {
    balance = balance + amount;
    return;
 }

specify a return type "SavingsAcc2" but don't return a value of that type. In fact, they don't return a value at all of any type. Either change the return type to void, meaning you won't be returning anything, or provide a value of type SavingsAcc2 in your return statement.

Other pointers
- indent your code properly.
- a method will return when it is done, a "return;" is not required.
- I don't know what you mean by "so that I can put together multiple methods in a single line." Can you show an example?

[Bear Bibeault]

Greg Brannon wrote:- I don't know what you mean by "so that I can put together multiple methods in a single line." Can you show an example?

I believe he's talking about "method chaining".

If the methods all return this, you can do things like:

something.doThis().doThat().doTheOtherThing();

It's really common in JavaScript, but not so much in Java APIs for some reason.

I frequently wish that the JavaBean standard had specified that setters return this. It'd make code so much terser.

If that's the intent, then all those return statements should be:

return this;

[Brian Burress]

Bear,

Thanks for the comments. I did not understand what what was envisioned either. Returning 'this' would solve the compile errors. While this would be 'legal' in a java sense, I question the value of coding methods to operate this way as you are limiting yourself to be able to do it only with methods which do not return anything.

If there is a need for the user to perform many method calls at once, perhaps a helper method which invokes them all would be a better approach. I digress from the main question a little, sorry!!

[Daniel Brackett]

Thank you Bear Bibeault! Success! and yes I was talking about method chaining!