Hey guys,
I am reading the Perl Camel book - Programming Perl 3rd Ed and having a bit
of trouble to understand some of the ideas presented in section 2.11.2.
Specifically it is told the following two statements are different:
1) if ($_ = <STDIN>) { print; } # suboptimal: doesn't test
defined
2) if (defined($_ = <STDIN>)) { print; } # best
But as I see it, these two do the same thing in that in the #1 one, the $_ =
<STDIN> expression returns an lvalue $_ which is then evaluated in the
boolean context provided by the "if" operator. Then it follows if $_ has the
"undef" value, then it would produce a "false" in the boolean context which
is conceptually the same as the 2nd expression.
Is there anything wrong in my understanding that somebody can straighten me
out?
flotsan
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