You could also use something like this: 
print "This is an integer\n" if int $input eq $input;

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Please note that it might at first glance seem more appropriate to use the numeric comparison operator ==, but this is not the case here. With the eq operator, you will detect that "4y" is not an integer, while with the == operator will silently do the conversion into an integer and report a wrong result.

Having said that, I would probably tend to prefer some of the regexes already mentioned such as /^\d+$/ or, used negatively, /\D/.

Je suis Charlie.

In reply to Re: using int and the range function by Laurent_R
in thread using int and the range function by Melderon

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