Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW
 
PerlMonks  

Re^2: Assignment to a value only if it is defined

by voj (Acolyte)
on Jan 21, 2010 at 16:48 UTC ( #818760=note: print w/replies, xml ) Need Help??


in reply to Re: Assignment to a value only if it is defined
in thread Assignment to a value only if it is defined

Thanks! That perfectly fits to assign to a scalar:

sub setifdef { $_[0] = $_[1] if defined($_[1]) } setifdef $foo, $bar;

And in case of a list I'll use the (slightly less readable) 'for grep defined,' psuedo-inline operator. It only makes sense with list references (if you treat (undef) as valid list). Defined scalar values which are transformed to a list can also be handled:

@list = @{$_} for grep defined, $listref_or_undef; @list = split(",",$_) for grep defined, $splitme_if_defined;

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://818760]
help
Chatterbox?
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others exploiting the Monastery: (3)
As of 2016-12-06 03:23 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    On a regular basis, I'm most likely to spy upon:













    Results (99 votes). Check out past polls.