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I guess my main question is so I don't have to check for null. Because.. if ((field !=null) && (!field.equals("text")) will work fine if field is null. But... if ((field == null) || (field.equals("text")) will fail if field is null with a null pointer exception error. So, to check for null or "" (basically a blank value) a little extra work is involved. I know it's safer to check for not equals, but sometimes it's nicer to not do that. Inevitably there will be a point where I will forget to check for null and my program will bomb at runtime with a null pointer exception. That's really what I want to avoid. But there's no *PSSR in Java. ;) Brad > -----Original Message----- > From: Joe Pluta [mailto:joepluta@plutabrothers.com] > Sent: Monday, March 26, 2001 11:58 AM > To: JAVA400-L@midrange.com > Subject: Re: field initializtion > > > What is "correct" depends on the usage. In some cases, a > zero-length string may be a valid return, with a null > indicating an error. For example, extra parameters for an > HTML tag would return "" if the tag was set to have no extra > parameters, but null if the tag has never been set up at all. > > That particular case aside, Java methods returning String > will commonly return null - this indicates that whatever > method is used to initialize the field was never invoked. > > As to initialization, instance variables of type String (or > indeed of any non-primitive type) are initialized to null. > Temporary variables are not initialized, and if the compiler > recognizes that you are attemping to use a field without > intializing it, it will generate a compile-time error. > > Finally, there is a little-discussed feature of the compiler > that says that when you assign a literal value to two > different String objects, they may actually get the exact > same address - this helps reduce heap space requirements. It > also allows two String literals to be compared using the == > and != operators, although I tend to avoid this particular > bit of "clever" coding. > > Joe > > > ---------- Original Message ---------------------------------- > From: "Stone, Brad V (TC)" <bvstone@taylorcorp.com> > Reply-To: JAVA400-L@midrange.com > Date: Mon, 26 Mar 2001 11:32:24 -0600 > > >What is more correct and why when creating local work fields > in a method? > > String newString = new String(); > or > String newString = null; > or > String newString = ""; > > How about when you're creating a class? I've read that a > class that returns > a null attribute is a pain in the arse. So, would you simple use the > constructor to change the value from null to ""? for example > > Class MyClass { > String value = null; > > public MyClass() { > value=""; > } > } > > +--- > | This is the JAVA/400 Mailing List! > | To submit a new message, send your mail to JAVA400-L@midrange.com. > | To subscribe to this list send email to JAVA400-L-SUB@midrange.com. > | To unsubscribe from this list send email to > JAVA400-L-UNSUB@midrange.com. > | Questions should be directed to the list owner: joe@zappie.net > +--- > > +--- > | This is the JAVA/400 Mailing List! > | To submit a new message, send your mail to JAVA400-L@midrange.com. > | To subscribe to this list send email to JAVA400-L-SUB@midrange.com. > | To unsubscribe from this list send email to > JAVA400-L-UNSUB@midrange.com. > | Questions should be directed to the list owner: joe@zappie.net > +--- > +--- | This is the JAVA/400 Mailing List! | To submit a new message, send your mail to JAVA400-L@midrange.com. | To subscribe to this list send email to JAVA400-L-SUB@midrange.com. | To unsubscribe from this list send email to JAVA400-L-UNSUB@midrange.com. | Questions should be directed to the list owner: joe@zappie.net +---
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