title: PHP function to check if a string is all lowercase
body: <p>I'm trying to create a function that returns TRUE if a string is all lowercase without using any built-in PHP functions. How can I do that?</p>
  <p>This is what I was working with, but using <a href="https://www.php.net/manual/en/function.ctype-lower.php" rel="nofollow noreferrer">ctype_lower</a>.</p>
  <pre><code>$string = &quot;string&quot;;
  
  if (ctype_lower($string)) {
      echo $string . ' is all lowercase letters.';
  } else {
      echo $string . ' is not all lowercase letters.';
  }
  </code></pre>