Wordpress Interview Questions and Answers

1. What are WordPress Hooks? Explain Action Hooks and Filter Hooks.

Answer:
Hooks allow developers to modify WordPress behavior without altering core files.

• Action Hooks: Execute custom code at specific points (e.g., init, wp_head).

  function custom_action() { echo "This is a custom action."; } add_action('wp_footer', 'custom_action');

• Filter Hooks: Modify data before it is displayed (e.g., the_content).

  function custom_filter($content) { return $content . "<p>Custom Filter Applied.</p>"; } add_filter('the_content', 'custom_filter');

2. How do you enqueue scripts and styles in WordPress?

Answer:
Use wp_enqueue_script() and wp_enqueue_style().

function custom_scripts() { wp_enqueue_style('custom-style', get_stylesheet_uri()); wp_enqueue_script('custom-js', get_template_directory_uri() . '/js/custom.js', array('jquery'), null, true); } add_action('wp_enqueue_scripts', 'custom_scripts');

3. How do you create a custom WordPress plugin?

Answer:

1. Create a folder in wp-content/plugins/

2. Create a PHP file, e.g., custom-plugin.php:

   <?php /* Plugin Name: Custom Plugin Description: A simple custom WordPress plugin. Version: 1.0 */ function custom_plugin_function() { echo "Hello from custom plugin!"; } add_action('wp_footer', 'custom_plugin_function');

4. What is the difference between WP_Query, query_posts(), and get_posts()?

Answer:

• WP_Query: The recommended method for fetching posts.

• query_posts(): Alters the main query (not recommended).

• get_posts(): Retrieves posts as an array without affecting the main query.

5. How do you create a custom post type in WordPress?

Answer:
Use register_post_type().

function create_custom_post_type() { register_post_type('custom_post', array( 'labels' => array('name' => 'Custom Posts'), 'public' => true, 'supports' => array('title', 'editor', 'thumbnail'), )); } add_action('init', 'create_custom_post_type');

6. What is the difference between get_template_part() and locate_template()?

Answer:

• get_template_part('file'): Loads a template part from the theme directory.

• locate_template(array('file.php')): Finds and includes a template file.

7. How do you disable the WordPress REST API?

Answer:
Use rest_authentication_errors.

function disable_rest_api($result) { return new WP_Error('rest_disabled', 'REST API is disabled', array('status' => 403)); } add_filter('rest_authentication_errors', 'disable_rest_api');

8. How do you customize the WordPress login page?

Answer:
Use login_enqueue_scripts.

function custom_login_style() { echo '<style>body { background-color: #f1f1f1; }</style>'; } add_action('login_enqueue_scripts', 'custom_login_style');

9. How do you create a custom WordPress widget?

Answer:
Use WP_Widget class.

class Custom_Widget extends WP_Widget { function __construct() { parent::__construct('custom_widget', 'Custom Widget'); } function widget($args, $instance) { echo '<p>Hello, this is a custom widget.</p>'; } } function register_custom_widget() { register_widget('Custom_Widget'); } add_action('widgets_init', 'register_custom_widget');

10. How do you add a custom column to the WordPress admin panel?

Answer:

function add_custom_column($columns) { $columns['custom_column'] = 'Custom Column'; return $columns; } function custom_column_content($column, $post_id) { if ($column == 'custom_column') { echo get_post_meta($post_id, 'custom_meta', true); } } add_filter('manage_posts_columns', 'add_custom_column'); add_action('manage_posts_custom_column', 'custom_column_content', 10, 2);

11. How do you create a shortcode in WordPress?

Answer:

function custom_shortcode() { return "This is a custom shortcode!"; } add_shortcode('custom', 'custom_shortcode');

Usage: [custom]

12. How do you optimize WordPress performance?

Answer:

• Use caching (WP Super Cache, W3 Total Cache).

• Optimize images (Smush, EWWW Image Optimizer).

• Minify CSS and JavaScript.

• Use a CDN (Cloudflare).

13. How do you schedule a cron job in WordPress?

Answer:

function custom_cron_job() { error_log("Cron job executed."); } if (!wp_next_scheduled('custom_cron_hook')) { wp_schedule_event(time(), 'hourly', 'custom_cron_hook'); } add_action('custom_cron_hook', 'custom_cron_job');

14. How do you add a custom REST API endpoint in WordPress?

Answer:

function custom_rest_api_endpoint() { register_rest_route('custom/v1', '/data/', array( 'methods' => 'GET', 'callback' => 'custom_api_callback', )); } function custom_api_callback() { return new WP_REST_Response(array('message' => 'Hello World'), 200); } add_action('rest_api_init', 'custom_rest_api_endpoint');

15. How do you restrict WordPress admin access?

Answer:

if (!current_user_can('administrator')) { wp_redirect(home_url()); exit; }

16. What is esc_html() used for?

Answer:
It escapes HTML characters to prevent XSS attacks.

17. How do you disable WordPress emojis?

Answer:

remove_action('wp_head', 'print_emoji_detection_script', 10); remove_action('wp_print_styles', 'print_emoji_styles', 10);

18. How do you remove WordPress version number from the source code?

Answer:

remove_action('wp_head', 'wp_generator');

19. How do you change the default WordPress login URL?

Answer:
Use plugins like WPS Hide Login or manually modify .htaccess.

20. How do you create a WordPress multisite?

Answer:
Add to wp-config.php:

define('WP_ALLOW_MULTISITE', true);

Then go to Tools → Network Setup.

21. How do you handle AJAX requests in WordPress?

Answer:

function custom_ajax_function() { echo 'AJAX Response'; wp_die(); } add_action('wp_ajax_custom_action', 'custom_ajax_function');

22. How do you create a custom user role?

Answer:

add_role('custom_role', 'Custom Role', array('read' => true, 'edit_posts' => true));

23. How do you prevent SQL injection in WordPress?

Answer:
Use $wpdb->prepare():

$wpdb->get_results($wpdb->prepare("SELECT * FROM wp_users WHERE ID = %d", $user_id));

24. How do you add custom capabilities to a user role?

Answer:

$role = get_role('editor'); $role->add_cap('edit_theme_options');

25. How do you implement object caching in WordPress?

Answer:
Use Redis or Memcached.

define('WP_CACHE', true);