Interview Questions for Front End Development

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The following questions will help you with preparing for your front end web development interview, or could serve as a refresher! They cover basic, entry-mid level topics in WordPress, AJAX, JSON, and best practices.

  1. What is the difference between server-side programming languages and client-side programming languages?

    Client-Side languages are open source and code is viewable in a web browser. Server-Side deals with the saving, retrieving, and processing of data, and the client-side deals with display and styling of data.

    Read More on StackExchange:

  2. What is JSON? When do you use JSON?

    JSON is a data format similar to XML. (It is NOT a language.) JSON stands for JavaScript Object Notation, but is not dependent on the use of JavaScript. It is used to share data between servers and through APIs.


    JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate… JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others.

  3. What is AJAX? Name a part of WordPress that uses AJAX.

    AJAX stands for asynchronous JavaScript and is used to send data without reloading a page. WordPress admin uses AJAX for plugin updates and comment moderation.

    From WordPress Codex:

    Currently, the core of WordPress uses Ajax only in the administration screens. For instance, Ajax is used for instant updates when you are doing comment moderation, and when you are adding and deleting items from lists such as categories, blogroll, and posts; Ajax is also the technology behind the auto-save functionality on post and page editing screens.

  4. What files are needed to create a WordPress theme?

    The only file required to have a theme show in the admin is the stylesheet – style.css. It must have a header, which includes Theme Name, Author, Description, Version, etc. To have an operational theme, an index.php file must be present.


  5. In WordPress, what is a Custom Post Type?

    Custom Post Types are a way to extend WordPress beyond posts and pages, but use the same structure and have the same features as both. A lot of plugins use them to create image sliders/galleries or event calendars.


  6. If you need to make changes to a WordPress plugin, what should you do?

    Best Way: Find the problem area, create a plugin, use remove_action() or remove_filter() to stop the action/filter from happening.

    Alternative: Contact the plugin author with details on what you’re trying to accomplish (after checking the support forum). They can determine whether it’s a bug or feature request and might be able to give you a solution or workaround.

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