Last word in string to uppercase with PHP

last-word-uppercase.php

function last_word_uppercase($sentence, $delimiter = ' ') {
    $words = explode($delimiter, $sentence);
    if (!empty($words)) {
        $lastWord = array_pop($words);
        $words[] = strtoupper($lastWord);
        return implode($delimiter, $words);
    }
 
    return strtoupper($sentence);
}

$str = 'This is a sentence.';
echo last_word_uppercase($str);