Re: basic oo question

[James Perkins <jrperkinsjr@xxxxxxxxx>]

You have a few options.
- Create a static isValid(String emailAddress) method that returns a
boolean.
- Create a static void validate(String emailAddress) method that throws an
exception.
- Create a boolean isValid() method and accept any, even invalid, strings
in the constructor.

Either way you don't really want to invoke that setter method from the
constructor. The "this.value" reference should be set instead.

Generally speaking I would go for isValid() method and accept any string. I
personally don't really like exceptions being thrown in constructors unless
it's something like a null check. Even then assertions can be better.

--
James R. Perkins


On Tue, Feb 21, 2012 at 13:58, Hockchai Lim
<lim.hock-chai@xxxxxxxxxxxxxxx>wrote:

> Assuming that I've a simply emailAddresss class that looks like below
>
> public class EmailAddress {
>
>    private String value = "";
>
>    public EmailAddress( String newValue )
>      setValue( newValue );
>    }
> . . .
> }
>
>
> Assuming that I now need to be able valid the emailAddress to make sure the
> value contains a valid email address.  In OO, what is the normal way to
> handle this:
> -> do I change the constructor to now throws an exception when newValue is
> not in valid email address format.
> or
> -> do I add a public method in this class that can be executed to determine
> if value contains valid email address after the EmailAddress object is
> created.
> or
> -> Do I create a new validation class that validate the EmailAddress
>
> thanks
>
>
> --
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