The really obvious way to do it is to make sure that the scalar doesn't contain a non-numeric character. 
if ($var && $var !~ /\D/) {
    # We have a value and it's a number
}

[download]
You need the initial check to make sure that $var actually contains something, otherwise the !~ will trigger a warning about unitialized variables.

So, you can code up a neato little function, sorta like: 

sub isNum {
    if ($var && $var !~ /\D/) {
        return 1;
    } else {
        return 0;
    }
}

[download]
Then, put that into a module of yours and have that module inherit from Exporter and you're all good! :)

(Yes, I'm sure someone's already done this, but this was too cool an opportunity to promote module use. *blush*)

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In reply to Re: Checking whether a $var is a number by dragonchild
in thread Checking whether a $var is a number by George_Sherston

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