How can incorrect HTML formatting affect the execution of PHP code?

Incorrect HTML formatting can affect the execution of PHP code by causing syntax errors or unexpected behavior. For example, missing closing tags or improperly nested elements can lead to parsing errors in the PHP code. To solve this issue, it's important to ensure that the HTML markup is well-formed and properly structured.

<?php
// Correct HTML formatting to avoid issues with PHP execution
echo "<html>
<head>
<title>Example</title>
</head>
<body>
<h1>Hello, World!</h1>
</body>
</html>";
?>