WP_Query class in Wordpress - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the <code>WP_Query</code> class in WordPress?

The <code>WP_Query</code> class is used to fetch posts from the WordPress database based on specific criteria like post type, category, date, and more. It helps display custom lists of posts.

beginner

How do you create a new WP_Query object to get the latest 5 posts?

You create it like this: <br>$query = new WP_Query(['posts_per_page' => 5]);<br>This fetches the 5 most recent posts.

beginner

What method do you use to check if a WP_Query has posts to show?

Use the have_posts() method. It returns true if there are posts matching the query, false otherwise.

intermediate

Explain the loop structure when using WP_Query to display posts.

You use a while loop:<br>while ($query->have_posts()) { $query->the_post(); /* display post */ }<br>This loops through each post and sets up post data for template tags.

intermediate

Why should you call wp_reset_postdata() after a custom WP_Query loop?

It restores the global $post variable to the main query’s current post. This prevents conflicts with other parts of the page that rely on the main query.

Which argument limits the number of posts returned by WP_Query?

A posts_per_page

B post_limit

C max_posts

D limit_posts

The correct argument is posts_per_page to limit how many posts are fetched.

What does the_post() do inside a WP_Query loop?

A Resets the query

B Sets up global post data for template tags

C Ends the loop

D Fetches the next post from the database

the_post() prepares global variables so template tags like the_title() work correctly.

Which method checks if there are posts available in a WP_Query object?

A get_posts()

B post_exists()

C query_posts()

D have_posts()

have_posts() returns true if the query has posts to loop through.

What is the purpose of wp_reset_postdata() after a custom query loop?

A Starts a new query

B Deletes the custom query

C Restores the main query’s post data

D Clears all posts from memory

It resets global post data to the main query to avoid conflicts.

How do you query posts from a specific category using WP_Query?

A Use 'category_name' argument

B Use 'cat_id' argument

C Use 'category' argument

D Use 'category_slug' argument

The correct argument is category_name with the category slug.

Describe how to use the WP_Query class to fetch and display posts with a custom loop.

Think about the steps to get posts and show them safely on a page.

Explain why resetting post data with wp_reset_postdata() is important after a custom query.

Consider what happens if you don’t reset after a custom loop.