Re: numbers and strings and regex?



Geoff Cox wrote: 
On Mon, 30 May 2005 18:30:42 +0100, Brian McCauley <nobull@xxxxxxxx>
wrote:

my $exnum = 0+$1;
>
this work fine but I'm not clear what the 

0+$1;

does? 

OK, let's break if down...

0 is the number zero.

+ is the numeric addition operator.

$1 is the captured string and since the capture was (\d{2}) it will be string like '01' or '07' or '42' or something like that.

Adding zero to a number does not change it.

But Perl has automatic type coercion so adding zero to a string tells Perl to coerce the string into a number.

Hense 0+'42' is the number 42 and 0+'07' is the number 7.
.

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