Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer
 
PerlMonks  

How exactly does no work?

by PerlOnTheWay (Scribe)
on Feb 16, 2012 at 11:19 UTC ( #954194=perlquestion: print w/ replies, xml ) Need Help??
PerlOnTheWay has asked for the wisdom of the Perl Monks concerning the following question:

use strict; + use warnings; sub c { no warnings; print $d; } sub a{ no warnings; print $b; c; } a();

The first Use of uninitialized value can be fixed by no warnings, but the second is reporting a fatal error,why?

Comment on How exactly does no work?
Download Code
Re: How exactly does no work?
by moritz (Cardinal) on Feb 16, 2012 at 11:24 UTC

    Warnings are not errors, and errors are not warnings.

    The fatal error comes from strict because you didn't declare $d. And because it comes from strict and not warnings, no warnings; has no effect on it. While you can say no strict 'vars';, it's much better to just declare $d with my.

      Why is it NOT fatal when I print $b; in sub a?

      Is no a run time or compile time thing?

      And it seems it's only effective in the current block, not in outer or inner block

        Minimal reference to the docs -- say perldoc -f no -- would put you on the path to answers. See also, as the docs suggest, use.

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: perlquestion [id://954194]
Approved by moritz
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others perusing the Monastery: (12)
As of 2014-09-17 16:45 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    How do you remember the number of days in each month?











    Results (91 votes), past polls