Question

I was wondering If I could get a regular expression which will match a string that only has alphabetic characters, and that alone.

Answer 1

You may use any of these 2 variants:

/^[A-Z]+$/i
/^[A-Za-z]+$/

to match an input string of ASCII alphabets.

• [A-Za-z] will match all the alphabets (both lowercase and uppercase).
• ^ and $ will make sure that nothing but these alphabets will be matched.

Code:

preg_match('/^[A-Z]+$/i', "abcAbc^Xyz", $m);
var_dump($m);

Output:

array(0) {
}

Test case is for OP’s comment that he wants to match only if there are 1 or more alphabets present in the input. As you can see in the test case that matches failed because there was ^ in the input string abcAbc^Xyz.

Note: Please note that the above answer only matches ASCII alphabets and doesn’t match Unicode characters. If you want to match Unicode letters then use:

/^\p{L}+$/u

Here, \p{L} matches any kind of letter from any language