Wordpress Interview Questions

WordPress is a free open source content management system (CMS) written PHP language and licensed under GPL.
It allows users to create dynamic websites from personal blogs to e-commerce. Wordpress current stable version as on Sept 2018 of WordPress is 4.9.8. You can download it free without any cost from https://wordpress.org/latest.zip.

First version of wordress is released in Year 2003

The following features of MySQL satisfy the use of MySQL in WordPress and make it easy for anyone to host their website.

• The widely available database server
• Extremely fast
• Open source
• Free of cost
• Supported by many low-cost Linux hosts.

The custom field in WordPress is a meta-data that allows the user to store the arbitrary information in the WordPress post. Using the custom field, other extra details can be added to the WordPress post.

WordPress’s query function allows you to execute any SQL query on the WordPress database. It is best used when there is a need for specific, custom, or otherwise complex SQL queries. For more basic queries, such as selecting information from a table, see the other wpdb functions above such as get_results, get_var, get_row or get_col.
Syntax

<?php $wpdb->query('query'); ?> 

Read more from https://codex.wordpress.org/Class_Reference/wpdb#Running_General_Queries

To disable comments in WordPress, Please follow below steps

• Step 1: Login to your WordPress admin panel.
• Step 2: Go to the Settings menu.
• Step 3: Under Settings menu click on Discussion.
• Step 4: Uncheck Allow people to post comments on new articles. checkbox
• Step 5: Click on save changes button, you done

In WordPress, Importers are plugins that provide the functionality to import a bulk XML file with any number of records. It enables to import Posts, Page, Custom Posts and Users data in an XML file.

In WordPress, a “taxonomy” is a grouping mechanism for some posts (or links or custom post types). There are four default taxonomies in WordPress they are

• Category
• Tag
• Link Category
• Post Formats

You are also free to create your custom taxonomies too.

Also, Read PHP Interview Questions

• PHP 7 or greater
• MySQL 5.6 or greater OR MariaDB 10.0 or greater
• The mod_rewrite Apache module
• HTTPS support(Recommended)

The user metafunction is used to retrieve the metadata of users. It can return a single value or an array of metadata.

Syntax is: get_user_meta( int $user_id, string $key = '', bool $single = false )

User id is the required user id parameter

Key is the optional parameter which is the meta key to retrieve. By default, it returns data for all key values.

Single is an optional parameter that tells whether the single value will return. By default, it is false.

Below are the basic steps that can be taken when your WordPress website is hacked

• Install security plugins like WP security
• Re-install the latest version of WordPress
• Change password and user-ids for all your users
• Check if all your themes and plug-ins are up-to-date
• Uninstall all plugins that are downloaded from untrusted places

Here are some of the features of WordPress.

• It’s Simplicity
• Easier publishing tools
• Search Engine Optimized
• User Management
• Media Management
• Easy Theme System
• Easy Extendability with Plugins
• Multilingual Support
• Easy Installation and Upgrades
• Multilingual Support
• Built-in Comments System
• Custom Content Types

Below is the list of plugins that comes with WordPress installation.
• Akismet
• Hello Dolly

Posts are timed and listed in chronological order with the latest posts at the top. Posts are meant to be shared and commented on.

Pages are static are static content, so an about us, contact us page etc. They are permanent and timeless entries.

There are two types hooks are available in WordPress, action hooks and filter hooks

They allow the user to, with short snippets of code, modify areas in a theme or plugin without modifying the original file.

• wp_options
• wp_users
• wp_links
• wp_commentmeta
• wp_term_relationships
• wp_postmeta
• wp_posts
• wp_term_taxonomy
• wp_usermeta
• wp_terms
• wp_comments

• Use of multiple plugins can make website heavy to load and slow
• Only utilizes PHP
• Sometimes updates can lead to loss of data, so you always need a backup copy
• Modifying images and tables are difficult.

• has_filter()
• add_filter()
• apply_filters()
• apply_filters_ref_array()
• current_filter()
• remove_filter()
• remove_all_filters()
• doing_filter()

Below are list of some Action hooks functions

• has_action()
• add_action()
• do_action()
• do_action_ref_array()
• did_action()
• remove_action()
• remove_all_actions()
• doing_action()

• get_header()
• wp_register()
• get_sidebar()
• wp_title()
• wp_enqueue_script()
• get_the_author()
• wp_list_authors()
• category_description()
• get_bookmarks()

Read More about WordPress template tags from https://codex.wordpress.org/Template_Tags

In WordPress, WP_DEBUG is a PHP constant (a permanent global variable) that can be used to trigger the “debug” mode throughout the website.

• In-built SEO system
• Flexibility
• Community
• Easy theme system
• Easy installation and upgrade
• Easy and flexible publishing option
• Multilingual is available in about more than 70 languages
• Own data full control and no unwanted advert on your personal or commercial website.

• Create a unique name.
• Create the folder of Plugin.
• Create a sub-folder for PHP files, translations, and assets.
• Create the main plug-in file and fill up the header information.
• Create activation and de-activation functions.
• Create an uninstall script.
• Create a readme.txt file.
• In case of detecting the paths to plug-in file, use proper functions and constants.