[jdom-interest] [Vote] NoSuchChildException

[Alex Chaffee]

>  Oh, wait, no, it only makes sense
> because in this case (getFirst() and getLast()) "null" has a different
> meaning.  It means "the first item in the list is null", not "there is
> no first item since the list is empty."

That also justifies its use in Iterator.  Since a collection may
contain null entries, you need an out-of-band way to signify "end of
list" as separate from "entry is null."  You will note that the
API-prescribed way to signify that is the hasNext() method.  The
exception is only thrown in the *exceptional* case that the programmer
ignored the result of hasNext().  (Which is a RuntimeException since
the programmer messed up.)

Kid Tested, Mother Approved -

 - Alex

-- 
Alex Chaffee                       mailto:alex at jguru.com
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