What common syntax errors can occur when setting PHP session variables?

Common syntax errors when setting PHP session variables include missing semicolons at the end of statements, using incorrect variable names, or forgetting to start the session with session_start(). To solve this issue, make sure to properly end statements with semicolons, use the correct variable names, and start the session before setting any session variables.

<?php
session_start();

$_SESSION['username'] = 'john_doe';
$_SESSION['email'] = 'john@example.com';
?>