PHP: is there an isLetter() function or equivalent?

Question

I am no PHP expert. I am looking for the PHP equivalent of isLetter() in Java, but I can't find it. Does it exist?

I need to extract letters from a given string and make them lower case, for example: "Ap.ér4i5T i6f;" should give "apéritif'. So, yes, there are accentuated characters in my strings.

`strtolower` will give you the lower-case string, but you'll likely need a regex to parse the input string and just get the alpha characters from it. — Brian Driscoll, Mar 15 '12 at 14:23

score 7 · Accepted Answer · answered Mar 15 '12 at 14:22

7

ctype_alpha().

answered Mar 15 '12 at 14:22

Oliver Charlesworth

252,669
29
530
650

2

Don't forget to use `setlocale()` because in the default C locale, only [a-zA-Z] will be considered as alphabetic characters (no accentuated characters) – SirDarius Mar 15 '12 at 14:25

score 2 · Answer 2 · answered Mar 15 '12 at 14:30

In addition to regex / preg_replace, you can also use strtoupper($string) and strtolower($string), if you need to universally upper-case a string. As Konrad mentioned, preg_replace is probably your best bet though.

http://php.net/manual/en/function.strtoupper.php

http://www.php.net/manual/en/function.strtolower.php

score 1 · Answer 3 · answered Mar 15 '12 at 14:24

In PHP (and in Java) you wouldn’t use isLetter to implement it, you’d rather replace all characters that aren’t letters using a regular expression:

echo preg_replace('/\P{L}/', '', input);

Loop up the documentation of preg_replace and the regex pattern syntax desciption, in particular the relevant Unicode character classes.

score 0 · Answer 4 · answered Mar 15 '12 at 14:25

0

You could probably use the php-slugs source code, with appropriate modifications.

answered Mar 15 '12 at 14:25

Cacovsky

2,445
3
19
26

PHP: is there an isLetter() function or equivalent?

4 Answers4

Linked