Hi choroba

Understood this and solved the situation for me.

 print /^(?:[A-Z_]+,?)+(?<!,)$/ ? 'good' : 'bad';

should be modified as

 print /^(?:[A-Z_0-9]+,?)+(?<!,)$/ ? 'good' : 'bad';

Lookahead and Lookbehind concepts is intresting. Thank you very much.

In reply to Re^4: regular expression to check if the textbox contains only special characters by Anonymous Monk
in thread regular expression to check if the textbox contains only special characters by rahulme81

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