15 lines
496 B
Perl
15 lines
496 B
Perl
$s = "";
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if ($s) { ... } # false
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# to tell if a string is false because it's empty, or it's plain not there (undefined)
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$s = undef;
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if (defined $s) { ... } # false; would be true on ""
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# though, perl implicitly converts between strings and numbers, so this is also false
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$s = "0";
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if ($s) { ... } # false; also false on "000", "0.0", "\x0", "0 with text", etc
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# but a string that converts to number 0 is not always false, though:
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$s = "0 but true";
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if ($s) { ... } # it's true! black magic!
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