I want to design a php try it yourself interpreter like we have in w3schools.com for CSS and JS. I googled plenty of stuff i could not find something helpful. What i have tried so far is:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
</head>
<body>
</div>
<form action="<?= $_SERVER["PHP_SELF"] ?>" method="POST">
<input type="submit">
<textarea name="code"><?= htmlentities($_POST["code"]) ?></textarea>
<div id="output">
<?= $_POST["code"] ?>
</div>
</body>
</html>
I have taken this code from on of the websites on web and honestly speaking its a part of my assignment, i just need some guidance.
You can use PHP Console
You can clone or download the ZIP file from official GitHub Page, and navigate to the path where you have installed via your browser.
Note: You need some tweaking if you want to use it online(on your website etc..)
Hope this helps. :)