Featured images in Wordpress - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this WordPress code snippet?

Consider this WordPress PHP code inside a theme template. What will it output if the current post has a featured image set?

Wordpress

<?php if (has_post_thumbnail()) {
  the_post_thumbnail('medium');
} else {
  echo 'No image available';
} ?>

A Causes a PHP syntax error

B Displays the featured image in medium size

C Outputs 'No image available' regardless of image

D Displays the full content of the post

💡 Hint

Think about what has_post_thumbnail() checks and what the_post_thumbnail() does.

The function has_post_thumbnail() checks if the current post has a featured image. If yes, the_post_thumbnail('medium') outputs the image in medium size. Otherwise, it prints the fallback text.

📝 Syntax

intermediate

Which option correctly sets a featured image for a post programmatically?

You want to set a featured image for a post using PHP code. Which snippet correctly assigns an image with attachment ID 123 to post ID 45?

A set_post_thumbnail(45, 123);

B set_post_thumbnail(123, 45);

C set_post_thumbnail(post_id=45, image_id=123);

D set_post_thumbnail(45);

💡 Hint

Check the order of parameters in the function.

The function set_post_thumbnail($post_id, $thumbnail_id) takes the post ID first, then the attachment ID of the image.

🔧 Debug

advanced

Why does this code fail to display the featured image?

This code is inside the loop but does not show the featured image. What is the likely cause?

Wordpress

<?php the_post_thumbnail('thumbnail'); ?>

A The image size 'thumbnail' is invalid

B the_post_thumbnail() must be called outside the loop

C The post does not have a featured image set

D Missing echo before the_post_thumbnail()

💡 Hint

Check if the post actually has a featured image assigned.

If the post has no featured image, the_post_thumbnail() outputs nothing. It does not cause an error.

🧠 Conceptual

advanced

What is the purpose of 'add_theme_support' with 'post-thumbnails' in WordPress?

Why do themes call add_theme_support('post-thumbnails'); in their functions.php file?

A To enable featured image support for posts and pages

B To automatically add thumbnails to all images in posts

C To register a new image size called 'post-thumbnails'

D To disable featured images site-wide

💡 Hint

Think about what 'post-thumbnails' feature means in WordPress.

Calling add_theme_support('post-thumbnails'); enables the featured image option in the WordPress admin for posts and pages.

❓ state_output

expert

What is the output of this code when no featured image is set?

Given this code in a WordPress template, what will be the output if the current post has no featured image?

Wordpress

<?php
if (has_post_thumbnail()) {
  the_post_thumbnail('large');
} else {
  echo '<img src="/images/default.jpg" alt="Default image">';
}
?>

A The featured image in large size

B No output at all

C A broken image icon because the path is wrong

D <img src="/images/default.jpg" alt="Default image">

💡 Hint

Check the else block and what it echoes.

If no featured image is set, the else block outputs an <img> tag with the default image path and alt text.