Valid PHP variable name as defined in the manual at http://php.net/manual/en/language.variables.basics.php

grabs the ID for the regex101.com permalink to code

Validates - URLs with schemes - http, https and ftp Relative URL starting with / and ../

Allows inserting expiry date as MM/YYYY or MM-YYYY format

Pattern matching and extracting color code formats using RegEx. https://github.com/Kyza/color-regex/

Allows phone numbers with optional country code, optional special characters and whitespace

RegEx email /^((?!\.)[\w-_.]*)(@\w+)(\.\w+(\.\w+)?)$/gim; Just playing with Reg Ex. This to validate emails in following ways ...

The secret of the Twitterverse.

Safe Password that allow only with a number, a lowercase, a uppercase, and a special character

general purpose HTTP URL regex

Capture comma separated numbers, no matter if there are spaces before or after the commas.