Pagination with custom queries in Wordpress - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this WordPress custom query pagination code?

Consider this WordPress loop with a custom query and pagination. What will be the output on the second page?

Wordpress

<?php
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args = [
  'post_type' => 'post',
  'posts_per_page' => 3,
  'paged' => $paged
];
$query = new WP_Query($args);
if ($query->have_posts()) :
  while ($query->have_posts()) : $query->the_post();
    the_title('<h2>', '</h2>');
  endwhile;
  echo paginate_links(['total' => $query->max_num_pages, 'current' => $paged]);
endif;
wp_reset_postdata();
?>

A Throws a fatal error because 'paginate_links' requires a query argument

B Displays posts 1 to 3 again because 'paged' is ignored, with pagination links

C Shows no posts because 'paged' is not set correctly, but pagination links appear

D Displays posts 4 to 6 with their titles and pagination links for total pages

💡 Hint

Check how the 'paged' parameter controls which posts appear on each page.

The 'paged' variable is set from the query var and passed to WP_Query. This makes the query fetch posts for the current page. So on page 2, posts 4 to 6 show. Pagination links are generated using the total pages from the query.

📝 Syntax

intermediate

Which option correctly sets up pagination for a custom WP_Query?

Choose the correct way to pass the current page number to a custom WP_Query for pagination.

A

$paged = get_query_var('page') ?: 1;
$args = ['paged' => $paged];

B

$paged = $_GET['page'] ?? 1;
$args = ['paged' => $paged];

C

$paged = get_query_var('paged') ?: 1;
$args = ['paged' => $paged];

D

$paged = get_query_var('paged') ?: 0;
$args = ['paged' => $paged];

💡 Hint

WordPress uses 'paged' query var for pagination, not 'page'.

The correct query var for pagination is 'paged'. Using get_query_var('paged') returns the current page number or empty if none. Using the null coalescing operator ?: sets it to 1 if empty. This is the standard way to get the current page for pagination.

🔧 Debug

advanced

Why does this custom query pagination always show the first page posts?

Look at this code snippet. Why does pagination not work and always show the first page posts?

Wordpress

<?php
$args = [
  'post_type' => 'post',
  'posts_per_page' => 5
];
$query = new WP_Query($args);
if ($query->have_posts()) :
  while ($query->have_posts()) : $query->the_post();
    the_title('<h3>', '</h3>');
  endwhile;
  echo paginate_links(['total' => $query->max_num_pages]);
endif;
wp_reset_postdata();
?>

A The 'paged' parameter is missing from the query args, so it always fetches page 1

B The 'posts_per_page' is too high, causing pagination to fail

C The 'paginate_links' function is called without 'current' parameter, causing wrong page

D The loop is missing wp_reset_postdata(), causing pagination to reset

💡 Hint

Check if the query knows which page to fetch.

Without the 'paged' argument, WP_Query always fetches the first page of posts. Pagination links may appear but clicking them won't change the posts shown because the query ignores the page number.

❓ state_output

advanced

What is the value of $query->max_num_pages after this custom query runs?

Assuming there are 12 published posts, what is the value of $query->max_num_pages after this query?

Wordpress

<?php
$args = [
  'post_type' => 'post',
  'posts_per_page' => 5,
  'paged' => 1
];
$query = new WP_Query($args);
// What is $query->max_num_pages?
?>

A 3

B 2

C 5

D 12

💡 Hint

Divide total posts by posts per page and round up.

There are 12 posts and 5 posts per page. 12 divided by 5 is 2.4, rounded up to 3 pages total. So max_num_pages is 3.

🧠 Conceptual

expert

Which option correctly explains why 'paged' must be passed to WP_Query for pagination?

Why is it necessary to pass the 'paged' parameter to a custom WP_Query when implementing pagination?

A 'paged' is only needed for default queries, not custom WP_Query instances

B 'paged' tells WP_Query which page of results to fetch; without it, the query always returns the first page

C 'paged' controls the number of posts per page; without it, no posts are returned

D 'paged' enables WordPress to cache query results for faster pagination

💡 Hint

Think about how WordPress knows which posts to show on page 2, 3, etc.

The 'paged' parameter tells WP_Query which page of posts to retrieve. If omitted, WP_Query defaults to page 1, so pagination links won't change the posts shown. This is essential for custom queries to support pagination.

Practice

1. What is the main purpose of using the paged parameter in a custom WordPress query?

easy

A. To order posts by date

B. To filter posts by category

C. To specify which page of posts to display for pagination

D. To limit the number of posts shown on the homepage

Solution

1. Step 1: Understand the role of paged in queries

   The paged parameter tells WordPress which page number of posts to fetch, enabling pagination.

2. Step 2: Differentiate from other query parameters

   Other parameters like category or order control filtering and sorting, not pagination.

3. Final Answer:

   To specify which page of posts to display for pagination -> Option C

4. Quick Check:

   paged controls page number in pagination [OK]

Hint: Remember: paged means page number for posts [OK]

Common Mistakes:

• Confusing paged with category filters
• Using paged to limit posts per page
• Ignoring the need to reset post data after custom queries

2. Which of the following is the correct way to include the paged parameter in a custom WP_Query to enable pagination?

easy

A. "page" => 1

B. "paged" => get_query_var('paged') ? get_query_var('paged') : 1

C. "paged" => 0

D. "pagination" => true

Solution

1. Step 1: Identify correct syntax for paged

   The correct way is to get the current page number using get_query_var('paged'), defaulting to 1 if not set.

2. Step 2: Check other options for correctness

   Options A, C, and D use wrong keys or values that won't work for pagination.

3. Final Answer:

   "paged" => get_query_var('paged') ? get_query_var('paged') : 1 -> Option B

4. Quick Check:

   Use paged with get_query_var for pagination [OK]

Hint: Use get_query_var('paged') or default to 1 [OK]

Common Mistakes:

• Using page instead of paged
• Setting paged to 0 disables pagination
• Using non-existent pagination parameter

3. Given this code snippet, what will be the output if the current page is 3?

$paged = get_query_var('paged') ? get_query_var('paged') : 1;
$args = [
  'post_type' => 'post',
  'posts_per_page' => 5,
  'paged' => $paged
];
$query = new WP_Query($args);
echo $query->query_vars['paged'];

medium

A. 1

B. 5

C. 0

D. 3

Solution

1. Step 1: Understand get_query_var('paged') behavior

   If the current page is 3, get_query_var('paged') returns 3, so $paged is 3.

2. Step 2: Check what is echoed

   The code echoes $query->query_vars['paged'], which is set to 3.

3. Final Answer:

   3 -> Option D

4. Quick Check:

   Current page number echoed = 3 [OK]

Hint: Echo query_vars['paged'] to see current page [OK]

Common Mistakes:

• Assuming default page 1 always prints
• Confusing posts per page with page number
• Expecting total posts count instead of page number

4. Identify the error in this pagination code snippet:

$paged = get_query_var('paged');
$args = [
  'post_type' => 'post',
  'posts_per_page' => 10,
  'paged' => $paged
];
$query = new WP_Query($args);
// Loop here
wp_reset_query();

medium

A. Missing default value for $paged, may cause page 0

B. Using wp_reset_query() instead of wp_reset_postdata()

C. Incorrect post type specified

D. Posts per page should be set to 5 for pagination

Solution

1. Step 1: Check $paged initialization

   $paged is set directly from get_query_var('paged') without defaulting to 1, so if no page is set, it may be 0 or empty.

2. Step 2: Evaluate other parts

   While wp_reset_postdata() is preferred after custom queries, the main error affecting pagination is missing default for $paged.

3. Final Answer:

   Missing default value for $paged, may cause page 0 -> Option A

4. Quick Check:

   Always default $paged to 1 if empty [OK]

Hint: Always default $paged to 1 to avoid page 0 [OK]

Common Mistakes:

• Not setting default page number
• Confusing wp_reset_query() with wp_reset_postdata()
• Assuming posts per page must be 5

5. You want to create a paginated list of 'product' posts showing 8 per page. Which code snippet correctly sets up the custom query and pagination, including resetting post data?

hard

A. $paged = get_query_var('paged') ?: 1;
$args = [
'post_type' => 'product',
'posts_per_page' => 8,
'paged' => $paged
];
$query = new WP_Query($args);
if ($query->have_posts()) {
while ($query->have_posts()) {
$query->the_post();
the_title();
}
}
wp_reset_postdata();

B. $paged = 1;
$args = [
'post_type' => 'product',
'posts_per_page' => 8
];
$query = new WP_Query($args);
while ($query->have_posts()) {
$query->the_post();
the_title();
}
wp_reset_query();

C. $paged = get_query_var('page') ?: 1;
$args = [
'post_type' => 'product',
'posts_per_page' => 8,
'paged' => $paged
];
$query = new WP_Query($args);
while ($query->have_posts()) {
$query->the_post();
the_title();
}
wp_reset_postdata();

D. $paged = get_query_var('paged') ?: 1;
$args = [
'post_type' => 'product',
'posts_per_page' => 8,
'page' => $paged
];
$query = new WP_Query($args);
if ($query->have_posts()) {
while ($query->have_posts()) {
$query->the_post();
the_title();
}
}
wp_reset_postdata();

Solution

1. Step 1: Correctly get current page number

   Use get_query_var('paged') ?: 1 to get current page or default to 1.

2. Step 2: Set query args and reset post data

   Use 'paged' => $paged (not 'page'), and call wp_reset_postdata() after the loop.

3. Step 3: Verify loop structure

   Check that the loop uses have_posts() and the_post() correctly.

4. Final Answer:

   Code snippet D correctly sets up pagination and resets post data -> Option A

5. Quick Check:

   Use paged param and wp_reset_postdata() [OK]

Hint: Use paged param and reset post data after loop [OK]

Common Mistakes:

• Using 'page' instead of 'paged' in query args
• Not resetting post data after custom query
• Hardcoding page number to 1 disables pagination