Could somebody help me create a regex that matches only characters?
Thanks in advance!
+3
A:
Use a character set: [a-zA-Z] matches one letter from A–Z in lowercase and uppercase. [a-zA-Z]+ matches one or more letters and ^[a-zA-Z]+$ matches only strings that consist of one or more letters only (^ and $ mark the begin and end of a string respectively).
If you want to match other letters than A–Z, you can either add them to the character set: [a-zA-ZäöüßÄÖÜ]. Or you use predefined character classes like the Unicode character property class \p{L} that describes the Unicode characters that are letters.
Gumbo
2010-09-01 12:09:15
That's a very ASCII-centric solution. This will break on pretty much any non-english text.
Joachim Sauer
2010-09-01 12:13:14
@Joachim Sauer: It will rather break on languages using non-latin characters.
Gumbo
2010-09-01 12:17:59
Already breaks on 90% of German text, don't even mention French or Spanish. Italian might still do pretty well though.
Ivo Wetzel
2010-09-01 12:22:32
@Gumbo: that depends on what definition of "latin character" you choose. J, U, Ö, Ä can all be argued to be latin characters or not, based on your definition. But they are all used in languages that use the "latin alphabet" for writing.
Joachim Sauer
2010-09-01 12:23:05
+3
A:
\p{L} matches anything that is a Unicode letter if you're interested in alphabets beyond the Latin one
RobV
2010-09-01 12:10:31
not in all regex flavours. For example, vim regexes treat `\p` as "Printable character".
Philip Potter
2010-09-01 12:12:28
[this page](http://www.regular-expressions.info/refflavors.html) suggests only java, .net, perl, jgsoft, XML and XPath regexes support \p{L}. But major omissions: python and ruby (though python has the regex module).
Philip Potter
2010-09-01 12:16:33
@Philip Potter: Ruby supports Unicode character properties using that exact same syntax.
Jörg W Mittag
2010-09-01 13:14:33
+1
A:
/[a-zA-Z]+/
Super simple example. Regular expressions are extremely easy to find online.
Scott Radcliff
2010-09-01 12:12:41
A:
Depending on your meaning of "character":
- [A-Za-z] --> all letters (uppercase and lowercase)
- [^0-9] --> all non-digit characters
Molske
2010-09-01 12:12:45
I meant lettters. It doesn't appear to be working though. preg_match('/[a-zA-Z]+/', $name);
Nike
2010-09-01 12:19:01
[A-Za-z] is just the declaration of characters you can use. You still need to declare howmany times this declaration has to be used: [A-Za-z]{1,2} (to match 1 or 2 letters) or [A-Za-z]{1,*} (to match 1 or more letters)
Molske
2010-09-01 13:06:41
A:
[\w]* matches whatever the regex engine thinks is a word character 0 or more times
Mike Cheel
2010-09-01 12:16:11
well technically 0-9 and _ are considered characters when talking about text. What I typed is technically correct. He didn't say just alphabet. He said characters.
Mike Cheel
2010-09-02 16:17:04