Using hash value as condition.

mephtu has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Using hash value as condition. by graff (Chancellor) on Mar 30, 2014 at 00:57 UTC
The point here is that "false" is not a reserved word (or a built-in function) in Perl, so it has no special meaning. In your snippet, it's treated as a "bareword", which you can look up under "B" in the perlglossary: A word sufficiently ambiguous to be deemed illegal under use strict 'subs'. In the absence of that stricture, a bareword is treated as if quotes were around it. In other words: `perl -le '$x = false; print length($x); print "x is ".join("-",split// +,$x)'` [download] (that will print out two lines: "5" and "x is f-a-l-s-e")	[reply] [d/l]
Re: Using hash value as condition. by hippo (Archbishop) on Mar 29, 2014 at 23:10 UTC
Not using strict and not using warnings. Either would have hinted at the reason.	[reply]
Re: Using hash value as condition. by AnomalousMonk (Archbishop) on Mar 30, 2014 at 04:11 UTC
For more insight as to why `'false'` is true in Perl, see Truth and Falsehood in perlsyn, also What is true and false in Perl?.	[reply] [d/l]
Re: Using hash value as condition. by NetWallah (Canon) on Mar 30, 2014 at 01:43 UTC
Another way to say it: `perl -E 'say "false is " , "false" ? "TRUE" :"FALSE"' false is TRUE` [download] What is the sound of Perl? Is it not the sound of a wall that people have stopped banging their heads against? -Larry Wall, 1992	[reply] [d/l]
Re: Using hash value as condition. by 7stud (Deacon) on Mar 29, 2014 at 23:37 UTC
...or what is this false thing in your code?	[reply]
Re: Using hash value as condition. by mephtu (Novice) on Apr 02, 2014 at 23:01 UTC
Many thanks. Perhaps now I can get some sleep.	[reply]