Regex/PHP Remove everything before first letter

Question

I need to remove all characters before the first letter... How do I search for the position of the first occurance of [az] & [AZ].

$test = "1234 123423-34 This is a test";

$string = preg_replace('/REGEX/', "", $test);
echo $string;

Should output: This is a test

Answer 1

Use a negated character class with a leading anchor.

^[^A-Za-z]+

Regex Demo: https://regex101.com/r/149aDt/1

PHP Demo: https://3v4l.org/7m6RZ

$test = "1234 123423-34 This is a test";
echo preg_replace('/^[^A-Za-z]+/', '', $test);

Answer 2

You can try this:

<?php
$test = "1234 123423-34 This is a test";
for($i=0;$i<strlen($test);$i++){
    if(!ctype_alpha($test[$i])){
        $test[$i] = '';
    }else{
        break;
    }
}
echo $test;

Answer 3

In addition to chris85 answer, if you want to deal with unicode characters:

$str = '123 μεγάλο τριχωτό της γάτας';
$result = preg_replace('~\PL+~Au', '', $str); 

Answer 4

You can use strcspn function to return the length of the initial string segment which does NOT matching any of the given characters, eg:

$position = strcspn($test, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");

This does not account for Unicode letters.

Also note that you can accomplish your task (replacement) with regular expressions, without the need to determine this position (see the other answer).