包含PHP与HTML没有正确交互[重复]

This question already has an answer here:

I'm trying to include some PHP script in with a HTML file, while I have found the command that achieves this, there seems to be an error in the way that I've layed out my code. I feel like I've missed a parentheses or something.

Here is a section of my HTML:

<title>Web Workers :: Home</title>
</head>
<body>

<?php
echo "<h1>Test</h1>";
include_once("htmlstatic.php");
?>

<nav id="navlist">
<ul>
<li class="links"> <a href="index.html">Home</a>                </li>
<li class="links"> <a href="topic1.html">Web Workers</a>        </li>
<li class="links"> <a href="register.html">Register</a>         </li>
<li class="links"> <a href="quiz.html">Quiz</a>                 </li>
<li class="links"> <a href="results.html">Results</a>           </li>
<li class="links"> <a href="about.html">About</a>               </li>
<li class="links"> <a href="enhancements.html">Enhancements</a> </li>
</ul>   
</nav>
<hr class="whitehr"/>
</body>
</html>

And here is my PHP:

<?php
echo "<h1>Web Workers</h1>";
echo "<hr class='whitehr'/>";
echo "<p>test</p>";
?>

Here is the output Output

</div>

Your file has .html extension that's why server cannot interpret the code starts with <?php

either tell server to interpret .html as .php or use .php file extension

for method first try below in .htaccess file

RemoveHandler .html .htm
AddType application/x-httpd-php .php .htm .html

You cannot include a .php file in .html file, nor can you execute a php code in a .html file, rename your .html to .php to execute the php code. For your php code to be interpreted your files must have .php extension.

Edited:
As you did not mention in the question i am assuming that you are using the default php installation, with no setting to include PHP files in an HTML file.