0+$1 for numeric, why?

nop has asked for the wisdom of the Perl Monks concerning the following question:

When I run this snippet

... elsif (/size(\d+)/) {
        $format->set_size($1); 
    } else ...
[download]

I get this error (under strict, warnings, and diagnostics)

Argument "_size" isn't numeric in multiplication (*) at
        D:/Perl/site/lib/Spreadsheet/Format.pm line 225 (#1)

    (W numeric) The indicated string was fed as an argument to an oper
+ator that
    expected a numeric value instead.  If you're fortunate the message
    will identify which operator was so unfortunate.
[download]

I can force $1 to be numeric by writing

        $format->set_size(0+$1);
[download]

but why do I have to do this?

Comment on 0+$1 for numeric, why? Select or Download Code

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Re: 0+$1 for numeric, why? by chipmunk (Parson) on Dec 02, 2000 at 00:03 UTC
I think that this warning is not caused by that snippet of code. At line 225, Spreadsheet::Format is trying to multiply the string "_size" by something. Your code snippet only calls set_size($1) when $1 contains a string of digits, so it could not be calling set_size("_size"). (If it were, adding 0 first would just get you a warning for the addition instead.) Can you edit Spreadsheet/Format.pm and see what is happening at line 225?	[reply]
Re: Re: 0+$1 for numeric, why? by nop (Hermit) on Dec 02, 2000 at 00:09 UTC
Here's the line from Format.pm... `$dyHeight = $self->{_size} * 20;` [download] But I am not sure I fully understand your comment....?	[reply] [d/l]
Re: Re: Re: 0+$1 for numeric, why? by chipmunk (Parson) on Dec 02, 2000 at 00:15 UTC
If you look back at the warning message you got, you see that it mentions "_size" as the string that is not numeric. Your code snippet will only set $1 to a string of digits, not to the string "_size", right? So, I don't think your code snippet is the problem. Regarding the line above: somehow, $self->{_size} is getting set to the string "_size", instead of to a number. Can you post more of the code from Spreadsheet/Format.pm? What method is line 225 part of? We'll just have to keep poking around the code until we figure this out.	[reply]