What are some common pitfalls to avoid when integrating PHP code into WordPress using plugins like "Insert PHP"?

One common pitfall to avoid when integrating PHP code into WordPress using plugins like "Insert PHP" is not properly sanitizing user input. This can lead to security vulnerabilities such as SQL injection or cross-site scripting attacks. To solve this issue, always sanitize and validate user input before using it in your PHP code.

// Example of sanitizing user input in WordPress
$user_input = $_POST['user_input'];
$sanitized_input = sanitize_text_field($user_input);