Re^3: What is true and false in Perl?

by ikegami (Patriarch)

on Sep 15, 2009 at 17:53 UTC ( #795439=note: print w/replies, xml )

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And by the way: You are not doing numeric addition on a string, you are evaluating "0 but true" in numeric context (to 0) - therefore no warning.

That makes no sense. The correct answer is that "0 but true" is special-cased.

$ perl -wle'print 0+"0 abc"'
Argument "0 abc" isn't numeric in addition (+) at -e line 1.
0

$ perl -wle'print 0+"0 but true"'
0
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Re^4: What is true and false in Perl? by Anonymous Monk on Apr 15, 2012 at 02:16 UTC
Only in the context of perl -e, as when run from a script, generates the same error (Argument "0 but true" isn't a numeric in addition (+) at line #. Also, both still print 0. And in both cases the attempt to add the string to 0 is ignored.	[reply]
Re^5: What is true and false in Perl? by AnomalousMonk (Archbishop) on Apr 15, 2012 at 02:42 UTC
Not quite sure what you are saying, but neither is behavior different when run as a 'script' versus on the command line via -e, nor is the arithmetic operation 'ignored'. `>cat 0_but.pl use warnings; use strict; print 42 * '0 but true', "\n"; print 42 * '0 but zonk', "\n"; >perl 0_but.pl 0 Argument "0 but zonk" isn't numeric in multiplication () at 0_but.pl +line 5. 0` [download] Update:* Verfied on ActiveState 5.8.9 and Strawberries 5.10.1, 5.12.3 and 5.14.2.	[reply] [d/l]

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