How do you separate your php code with html code?

Question

Should I do this?
<?php if ($is_admin): ?>
<?php include 'navigation-admin.php'; ?>
<!-- html code -->
<?php endif; ?>

Or this?
<?php
if ($is_admin):
include 'navigation-admin.php';
?>
<!-- html code -->
<?php endif; ?>

Answer 1

in html u could add your code of php in the body tag while the better way is to include or require the .php file