[TOC] ## 实例 ``` $orig = "I'll \"walk\" the <b>dog</b> now"; $a = htmlentities($orig); echo $a.PHP_EOL; // I'll &quot;walk&quot; the &lt;b&gt;dog&lt;/b&gt; now $b = htmlspecialchars($orig); echo $b.PHP_EOL; // I'll &quot;walk&quot; the &lt;b&gt;dog&lt;/b&gt; now $a1 = html_entity_decode($a); echo $a1.PHP_EOL; // I'll "walk" the <b>dog</b> now $b1 = htmlspecialchars_decode($b1); echo $b1.PHP_EOL; // I'll "walk" the <b>dog</b> now ```