Regular Expression in C# for Last Name that includes internal space

Question

I'd like a Regular Expression for C# that matches "Johnson", "Del Sol", or "Del La Range"; in other words, it should match words with spaces in the middle but no space at the start or at the end.

Answer 1

The ? qualifier is your friend. Makes a shortest-possible match instead of a greedy one. Use it for the first name, as in:

^(.+?) (.+)$

Group 1 grabs everything up to the first space, group 2 gets the rest.

Of course, now what do you do if the first name contains spaces?

Answer 2

Try something like this:

^[^\s][\w\s]*[^\s]$

Answer 3

This should do the job:

^[a-zA-Z][a-zA-Z ]*[a-zA-Z]$

Edit: Here's a slight improvement that allows one-latter names and hyphens/apostrophes in the name:

^[a-zA-Z'][a-zA-Z'- ]*[a-zA-Z']?$

Answer 4

^\p{L}+(\s+\p{L}+)*$

This regex has the following features:

• Will match a one letter last name (e.g. Malcolm X's last name)
• Will not match last names containing numbers (like anything with a \w or a [^ ] will)
• Matches unicode letters

But what about last names like "O'Connor" or hyphenated last names ... hmm ...

Answer 5

I think this is more what you were looking for:

^[^ ][a-zA-Z ]+[^ ]$

This should match the beginning of the line with no space, alpha characters or a space, and no space at the end.

This works in irb, but last time I worked with C#, I've used similar regexes:

(zero is good, nil means failed)

>> "Di Giorno" =~ /^[^ ][a-zA-Z ]+[^ ]$/
=> 0
>> "DiGiorno" =~ /^[^ ][a-zA-Z ]+[^ ]$/
=> 0
>> " DiGiorno" =~ /^[^ ][a-zA-Z ]+[^ ]$/
=> nil
>> "DiGiorno " =~ /^[^ ][a-zA-Z ]+[^ ]$/
=> nil
>> "Di Gior no" =~ /^[^ ][a-zA-Z ]+[^ ]$/
=> 0

Answer 6

In the name "Ṣalāḥ ad-Dīn Yūsuf ibn Ayyūb" (see http://en.wikipedia.org/wiki/Saladdin), which is the first name, and which is the last? What about in the name "Roberto Garcia y Vega" (invented)? "Chiang Kai-shek" (see http://en.wikipedia.org/wiki/Chang_Kai-shek)?

Spaces in names are the least of your problems! See http://stackoverflow.com/questions/620118/personal-names-in-a-global-application-what-to-store.