Post meta basics in Wordpress - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this code when retrieving post meta?

Consider a WordPress post with ID 42 that has a meta key 'color' with value 'blue'. What will be the output of the following code?

echo get_post_meta(42, 'color', true);

Wordpress

echo get_post_meta(42, 'color', true);

A blue

B null

C Array containing 'blue'

D Error: Undefined function

💡 Hint

The third parameter controls if the function returns a single value or an array.

When the third parameter is true, get_post_meta returns a single value, which is the meta value 'blue'.

❓ state_output

intermediate

What is the value of $meta after this code runs?

Given a post with ID 10 that has two meta values for key 'tags': 'php' and 'wordpress', what is the value of $meta?

$meta = get_post_meta(10, 'tags', false);

Wordpress

$meta = get_post_meta(10, 'tags', false);

A ['php', 'wordpress']

B 'php'

C null

D Error: Invalid argument

💡 Hint

The third parameter false returns all meta values as an array.

When the third parameter is false, get_post_meta returns an array of all meta values for the key.

📝 Syntax

advanced

Which option correctly adds a post meta key 'rating' with value 5?

You want to add a meta key 'rating' with value 5 to post ID 15. Which code snippet is correct?

A add_post_meta('15', rating, '5');

B add_post_meta(15, 'rating', 5);

C add_post_meta(15, 'rating');

D add_post_meta(15, 'rating', 5, true);

💡 Hint

Check the function parameters: post ID, meta key, meta value, and optional unique flag.

Option B correctly uses add_post_meta with post ID as integer, meta key as string, and meta value as integer.

🔧 Debug

advanced

Why does this code fail to update post meta?

The developer tries to update the meta key 'views' for post ID 20 but it does not change. What is wrong?

update_post_meta(20, 'views');

Wordpress

update_post_meta(20, 'views');

A update_post_meta requires the meta key to be an integer.

B Post ID 20 does not exist, so update fails.

C Missing the new meta value parameter, so the function does nothing.

D The meta key 'views' is reserved and cannot be updated.

💡 Hint

Check the function signature for update_post_meta.

update_post_meta requires three parameters: post ID, meta key, and new meta value. Missing the value causes failure.

🧠 Conceptual

expert

What happens if you call get_post_meta with a non-existent meta key and third parameter true?

If you call get_post_meta(30, 'nonexistent_key', true) on a post with ID 30 that has no such meta key, what is returned?

Wordpress

get_post_meta(30, 'nonexistent_key', true);

A null

B false

C An empty array []

D An empty string ''

💡 Hint

Check the WordPress documentation for get_post_meta return values when meta key is missing.

When the third parameter is true and the meta key does not exist, get_post_meta returns an empty string.