How can the context switch from PHP to HTML be managed effectively when echoing values in form elements in PHP?

When echoing values in form elements in PHP, the context switch from PHP to HTML can be managed effectively by using the PHP opening and closing tags within the HTML code. This allows you to seamlessly switch between PHP and HTML without breaking the syntax. By embedding the PHP code within the HTML elements, you can easily populate form fields with dynamic values generated by PHP.

<input type="text" name="username" value="<?php echo isset($_POST['username']) ? $_POST['username'] : ''; ?>">