Debugging with WP_DEBUG in Wordpress - Practice Problems & Coding Challenges

Challenge - 5 Problems

🔧 Debug

intermediate

What happens when WP_DEBUG is set to true?

In a WordPress site, if you set define('WP_DEBUG', true); in wp-config.php, what is the expected behavior?

A Nothing changes; WP_DEBUG has no effect.

B The site will automatically fix all PHP errors.

C The site will disable all plugins to prevent errors.

D PHP errors and warnings will be displayed on the site pages.

💡 Hint

Think about what debugging means and what showing errors helps with.

Setting WP_DEBUG to true tells WordPress to show PHP errors and warnings on the site. This helps developers find and fix problems.

❓ component_behavior

intermediate

Effect of WP_DEBUG_DISPLAY set to false

If WP_DEBUG is true but define('WP_DEBUG_DISPLAY', false); is also set, what will happen?

A Errors will be logged but not shown on the site pages.

B Errors will be shown on the site pages and logged.

C Errors will cause the site to crash immediately.

D Errors will be neither logged nor shown.

💡 Hint

Think about separating error display from error logging.

When WP_DEBUG_DISPLAY is false, errors are hidden from the site pages. They are neither logged nor shown unless WP_DEBUG_LOG is enabled.

📝 Syntax

advanced

Correct way to enable error logging in WordPress

Which code snippet correctly enables error logging to a file in WordPress?

A

define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);

B

define('WP_DEBUG', true);
define('WP_DEBUG_LOG', 'false');

C

define('WP_DEBUG', false);
define('WP_DEBUG_LOG', true);

D define('WP_DEBUG_LOG', true);

💡 Hint

Both WP_DEBUG and WP_DEBUG_LOG must be true to log errors.

To log errors, WP_DEBUG must be true and WP_DEBUG_LOG must also be true. This combination enables logging to wp-content/debug.log.

❓ state_output

advanced

What file stores logged errors when WP_DEBUG_LOG is true?

When WP_DEBUG_LOG is set to true, where does WordPress save the error logs by default?

A wp-content/uploads/error.log

B wp-content/debug.log

C wp-includes/error.log

D root directory error.log

💡 Hint

Think about the folder where WordPress stores content files.

By default, WordPress saves error logs to wp-content/debug.log when WP_DEBUG_LOG is true.

🧠 Conceptual

expert

Why avoid enabling WP_DEBUG on a live site?

Why is it generally not recommended to have WP_DEBUG set to true on a live WordPress site?

A Because it automatically deletes all user data.

B Because it disables all caching, slowing down the site.

C Because it can expose sensitive error details to visitors, risking security.

D Because it prevents plugins from updating.

💡 Hint

Think about what showing errors publicly might reveal.

Enabling WP_DEBUG on a live site can show error messages to visitors, which might reveal sensitive information and create security risks.