Regular expression for validating first name Online sex chat no credet card no sign up
Input validation is the practice of limiting the data that is processed by your application to the subset that you know you can handle.
This means going beyond simple data types and diving deeply into understanding the ideal data type, range, format and length for each piece of data.
I suggest striking a balance between readability and restriction such as: This will match the majority of e-mail addresses, but will reject the museum TLD and some very fringe e-mail addresses.
This regular expression will match one or more (via the plus sign) upper or lowercase letters (a-z or A-Z).
We can easily add those to the whitelist like so: Now we can see that S4MMIE, user-name, Mr. Phone Numbers Phone numbers can be difficult if you start getting into international numbers and complicated formats.
I like to strip everything out, but the digits, then make a very quick check to see if there are 10 numbers.
e-mail address e-mail addresses are notoriously difficult to match if you get too caught up in the RFC.
Additionally if you try to be too compliant you may open yourself up to other issues, such as command or SQL injection or Cross Site Scripting.
This free regular expression tester lets you test your regular expressions against any entry of your choice and clearly highlights all matches.