Question

I recently asked for and received help regarding a Java regular expression that would match a string containing a maximum of two asterisks, which could be the first or last character, or both. This was the answer I accepted:

^\\*?[^*]+\\*?$

Naturally, the requirements have now changed and I need to further constrain the string such that it can only contain either lower or upper case letters, spaces or the asterisk wildcard character. No numbers or punctuation (other than *) are allowed. The constraints on the wildcard positioning remain as described above.

So these strings would be matched:

foo
f oo
*Foo
FOO *
*foo*
*F o o*

And these strings would not:

*
**
**foo
*f*oo
1
*1
_
foo1*
_foo
%foo^

I have spent ages trying to work this out and haven’t been able to, even using RegexBuddy. I don’t really like asking such a specific question on Stack Overflow, but I just can’t get to the solution on my own.

Thanks in advance.

Answer 1

This should work:

^\\*?[a-zA-Z ]+\\*?$