On Oct 1, 2012, at 2:44 AM, li panda wrote:
> Here is two beginners questiones ~ to trouble you
>
> 1.print "This is the ${times}th time.\n";
> what is the function of "{}"
The "{}" in ${times} specify that the value of the scalar variable $times
should be interpolated into the string and followed by the characters "th".
Without the {}, the string would be " ... $timesth ... ", and Perl would look
for the $timesth variable instead of $times.
>
> 2.print "0x30" + 0, "\n";
> why output is 0 not 0x30
>
The plus sign forces Perl to evaluate the arithmetic expression "0x30" + 0. The
string "0x30" will evaluate to the numerical value 0, because Perl scans the
string from left-to-right, accepting and processing all valid numerical
characters. When it gets to the 'x', it stops, returning a value of zero. The
Perl string parser does not evaluate hexadecimal strings.
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