htmlspecialchars strip_tags

<?php

$str = "This is some <b>bold</b> text.";
echo htmlspecialchars($str);
echo '<br>';
echo strip_tags($str);

?>
<hr>
<?php
echo strip_tags("Hello <b>world!</b>");
?>

This is some &lt;b&gt;bold&lt;/b&gt; text.<br>This is some bold text.<hr>
Hello world!