PHP: Extract Alphabetical Sequences from a String

This function extracts alphabetical sequences (usually words) from a string (text):

function extract_alphabetical_sequences($string)
{
preg_match_all('/([a-zA-Z]+)/', $string, $match);

return $match[0];
}

$string = 'In hac habitasse platea dictumst. 54 8*5 5#$&*^@  $ @ In eget sem. Etiam quam. Nam nec, justo sed lorem, auctor tincidunt. Nulla id risus laoreet nisl  *^$&&@#$ egestas ultrices.';

$alpha_array = extract_alphabetical_sequences($string);

echo '<pre>'; print_r($alpha_array); echo "</pre>";

Output:

Array
(
    [0] => In
    [1] => hac
    [2] => habitasse
    [3] => platea
    [4] => dictumst
    [5] => In
    [6] => eget
    [7] => sem
    [8] => Etiam
    [9] => quam
    [10] => Nam
    [11] => nec
    [12] => justo
    [13] => sed
    [14] => lorem
    [15] => auctor
    [16] => tincidunt
    [17] => Nulla
    [18] => id
    [19] => risus
    [20] => laoreet
    [21] => nisl
    [22] => egestas
    [23] => ultrices
)

If you need to extract all the words from a string, consider using the str_word_count() function.