can't seem to get php working in MAMP

I'm trying to learn php and step one is getting php working in some capacity. I'm attempting to use MAMP but I'm having some trouble.

Specifically: if I create a file with the below code and save it as index.html in MAMP's "Document Root" directory, I get a blank page when pointing my browser at http://localhost:8888/index.html.

Code:

<html>
<body>

    <?php
    echo "Hello World!";
    ?>

</body>
</head>

Alternatively, if I put a bit of php into its own file (say test.php) and then point my browser at this file, it just displays the full text of the file in the browser.

Any ideas what I might be doing wrong?

Solution

You must save a file with PHP inside it with a .php extension. So you would need to name it index.php instead of index.html. Simple fix.