It validates an email address with alias

with Leap Year support (dd/MM/yyyy)

match with or without prevailing/trailing slashes

get special tag contains html link

Remove multiple white spaces between words and replace it with the char of your choosing.

Extract parts of an URL.

RegEx for an .htaccess rewrite into a subfolder without provoking a 'too many redirects' error

^((?!proposed_).)*((project|task)_details) matches: project_details task_details...

This expression matches human genomic coordinates, similat to those being used by genome browsers (e.g. the UCSC Genome Browser). It can match: chromosome, chromosome start, chromosome start end, chromosome start end reference sequence, chromosome start end reference sequence alternative sequence. T...

URL MATCH

Eircode validation for new postcodes identifiers in Republic of Ireland. Case-insensetive for easier user input. Added optional space separator to follow same pattern as in UK post codes and in examples used in eircode spec.

It won't match single line comments like this one: //* This comment won't be match */ ^ see the double / Works in PHP without the g modifier.