How to extract word from a string given a position in php

extract_word_test

<?php

for ($i = 0; $i <= 30; $i++) {
    $test = extractWord("durchfall fieber kinder", $i);
    echo $i . ": " . $test . "\n";
}

function extractWord($text, $position) {
    $words = explode(' ', $text);
    $characters = -1;
    foreach ($words as $word) {
        $characters += strlen($word) + 1;
        if ($characters >= $position) {
            return $word;
        }
    }
    return '';
}