CODEWITHSUNDEEP
javamethods
RnD
RnD

Reputation: 1069

Java return value only from within a loop

I have a method where I need to return a specific object if found, otherwise throw an exception. So I wrote the following: 

public CustomerDetails findCustomer( String givenID ) throws CustomerNotFoundException{
    for(CustomerDetails nextCustomer : customers){
        if(givenID == nextCustomer.getCustomerID()){
            return nextCustomer;
        }else{
            throw new CustomerNotFoundException();
        }
    }
}

But it requires me to add a return statement at the bottom of the method. Is there a way to ignore this?

Upvotes: 0

Views: 81

Answers (6)

Sedat Polat
Sedat Polat

Reputation: 1721

If the customer could not be found in the loop, it should throw exception out of the loop. Also you should use ".equals" instead of "==", because "givenID" is an object.

public CustomerDetails findCustomer( String givenID ) throws CustomerNotFoundException {
    for (CustomerDetails nextCustomer : customers) {
        if (givenID.equals(nextCustomer.getCustomerID())){
            return nextCustomer;
        }
    }
    throw new CustomerNotFoundException();
}

Upvotes: 0

DasBooten
DasBooten

Reputation: 339

You can just add a return; at the end of your method. It won't be accessible so it won't cause issues.

You could also use a try catch around your loop. Here is a handy tutorial for that if you wish to follow this route. http://tutorials.jenkov.com/java-exception-handling/basic-try-catch-finally.html

Upvotes: 0

Christian
Christian

Reputation: 395

An exception should be thrown if an unexpected behavior occurs. A failed search is not an exception, but a rarely common cause.

For the reason of good design, you should not throw the exception. Instead you can expand your calling method to test the result for null-iness or similiar.

Upvotes: 0

Jens
Jens

Reputation: 69495

You can return the object if it is found. If it will be not found it throw an exception at end of the loop:

public CustomerDetails findCustomer( String givenID ) throws CustomerNotFoundException{
    for(CustomerDetails nextCustomer : customers){
        if(givenID.equals(nextCustomer.getCustomerID())){
            return nextCustomer;
       }
    }
       throw new CustomerNotFoundException();
}

Note. you compare strings with ==. Here you have to usethe equals method!

Upvotes: 1

TheLostMind
TheLostMind

Reputation: 36304

Change your code to :

public CustomerDetails findCustomer( String givenID ) throws CustomerNotFoundException{
    for(CustomerDetails nextCustomer : customers){
        if(givenID == nextCustomer.getCustomerID()){
            return nextCustomer;
        }
    }
    throw new CustomerNotFoundException();
}

Upvotes: 3

Konstantin Yovkov
Konstantin Yovkov

Reputation: 62874

It asks you to provide a valid outcome from the method for the case when the loop is not executed (i.e. customers is empty). You have to do this:

for (CustomerDetails nextCustomer : customers){
    if (givenID == nextCustomer.getCustomerID()){
        return nextCustomer;
    }
}
throw new CustomerNotFoundException();

because otherwise you would throw the exception after the first element that doesn't meet the condition provided in the if.

Upvotes: 6

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