Re: "Safe" print?

If you want undefined values printed as "undef", try

use 5.010;
print $somevalue // "undef";
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Comment on Re: "Safe" print? Download Code

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Re^2: "Safe" print? by sundialsvc4 (Abbot) on May 14, 2013 at 13:45 UTC
... noting that the `"//"` operator is, IIRC, a relatively recent addition to the language. You should have it, but you (or some backwater web-hosting companies who need not be named ...) conceivably might not. See `perldoc perlop` on your system; look for the heading “C-style Logical Defined-Or.”
Re^3: "Safe" print? by ambrus (Abbot) on May 14, 2013 at 14:41 UTC
See that first line in my the code? It says `use 5.010;`. The `//` operator was new in perl 5.10. It's not new anymore now.	[reply] [d/l] [select]
Re^4: "Safe" print? by dd-b (Monk) on May 14, 2013 at 19:17 UTC
And that's right where I am (CENTOS 6 packaged Perl). I know and heartily approve the "//" operator (except when I somehow get confused and use backslashes), but don't want to have to write special code each time I print something that I can't prove is defined quickly. However, the Dumper suggestion (and related) is useful, I'm just embarrassed I didn't think of it myself (that's for complex structures! In debugging!).	[reply]
Re^5: "Safe" print? by ambrus (Abbot) on May 14, 2013 at 21:13 UTC
Re^3: "Safe" print? (perldelta) by LanX (Saint) on May 14, 2013 at 15:20 UTC
> ... noting that the "//" operator is, IIRC, a relatively recent addition to the language. Googling perldelta defined-or quickly leads to http://perldoc.perl.org/5.10.0/perldelta.html#Defined-or-operator (update: Perl 5.10.0 released Dec 2007) So even if you ignore ambrus' `use 5.010` there is no need to "IIRC" instead of checking! > See perldoc perlop on your system; look for the heading “C-style Logical Defined-Or.” see What shortcuts can I use for linking to other information? Cheers Rolf ( addicted to the Perl Programming Language)	[reply] [d/l]

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