Regex only allow alphanumeric

Question

I am trying to do the following with regex...

• Only A-Z and 0-9
• Not one character in its own
• Can not be just numbers on their own
• Can be just letters on their own but at least 2 characters

I have this so far http://regex101.com/r/yW1pV8 ...

.*[a-zA-Z]{2,}+.*

This seems to meet my critera except that it doesn't stop me from putting in other charactes such as $ _ ! etc...

Some correct test data is...

579 International Road
International Road

Some incorrect data is...

679
3
$£
A

Where am I going wrong?

Answer 1

.* matches anything, which isn't what you want it seems. Also, you don't need the +, since X{n,} already means X at least n times. Lastly, you forgot the 0-9 part. So it looks like this will do:

[a-zA-Z0-9]{2,}

Some regex flavors have [a-zA-Z0-9] as a pre-defined character class. For example, in Java it's \p{Alnum}.

If you also want to allow for spaces (as per your test data), use \s:

(?:\s*[a-zA-Z0-9]{2,}\s*)*