How to ensure password complexity requirements?
Ensure that user's passwords are sufficiently complex
Everything you need to know about writing regular expressions for PHP.
Ensure that user's passwords are sufficiently complex
Matching things like https://www.phpliveregex.com
Matching email addresses (it doesn't need to be hard!)
Matching things like 201-867-5309
Good for validating user-generated parts of URLs
Keep your usernames from getting too crazy
Good for matching zip and postal codes in US, UK and Canada