function limit_text($text, $limit) {

      if (str_word_count($text, 0) > $limit) {

          $words = str_word_count($text, 2);

          $pos = array_keys($words);

          $text = substr($text, 0, $pos[$limit]) . '...';

      }

      return $text;

    }

echo limit_text('Hello here is a long sentence blah blah blah blah blah hahahaha haha haaaaaa', 5);

輸出：

Hello here is a long ...

將數字更改3為以下數字20可獲得前20個字，或將其作為參數傳遞。下面演示了如何獲取前3個字：（因此將更3改為20可以更改默認值）：

function first3words($s, $limit=3) {

    return preg_replace('/((\w+\W*){'.($limit-1).'}(\w+))(.*)/', '${1}', $s);   

}

var_dump(first3words("hello yes, world wah ha ha"));  # => "hello yes, world"

var_dump(first3words("hello yes,world wah ha ha"));   # => "hello yes,world"

var_dump(first3words("hello yes world wah ha ha"));   # => "hello yes world"

var_dump(first3words("hello yes world"));  # => "hello yes world"

var_dump(first3words("hello yes world.")); # => "hello yes world"

var_dump(first3words("hello yes"));  # => "hello yes"

var_dump(first3words("hello"));  # => "hello"

var_dump(first3words("a")); # => "a"

var_dump(first3words(""));  # => ""