Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight
 
PerlMonks  

Re: Re: getting 0 to print

by rbc (Curate)
on Jan 13, 2003 at 23:32 UTC ( #226649=note: print w/ replies, xml ) Need Help??


in reply to Re: getting 0 to print
in thread getting 0 to print

Oooh! that work too! thanks!

I have never seen this ...

$_ = "" => next unless defined;
... before. Could you explain how that works.
It would be most enlightening.


Comment on Re: Re: getting 0 to print
Download Code
Re: Re: Re: getting 0 to print
by Arien (Pilgrim) on Jan 14, 2003 at 00:08 UTC

    I have never seen this ...

    $_ = "" => next unless defined;

    ... before. Could you explain how that works.

    I'm not sure what part puzzles you, so...

    • defined implicitly refers to $_.
    • unless (...) { ... } can be written as ... unless ... if the block is just a simple statement.
    • ... => ... is another way to write ... , ... (apart from the fact that => will autoquote any word left of it).
    • In scalar context (ie the way used here) the comma (in either notation) evaluates its both arguments from left to right (and returns the value value of the last argument evaluated).

    (You can find all details in perlsyn and perlop.)

    In other words, that line is just one of the many variations of writing:

    unless (defined $_) { $_ = ""; next }

    — Arien

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://226649]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others surveying the Monastery: (15)
As of 2014-07-29 14:18 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (217 votes), past polls