If a character class starts with ^, it is a negated character class. That is, it will match any character that is not in the class. So, /[^a-zA-Z0-9]/ will match any character that is not a letter or digit.

See perlretut for a tutorial on regexps and perlre for the details.

update: My 200th node :)

In reply to Re^3: check if string contains anything other than alphanumeric by FunkyMonk
in thread check if string contains anything other than alphanumeric by Anonymous Monk

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