As a web developer, having a strong grasp of XHTML is crucial for creating standards-compliant and accessible websites. With its XML-based syntax, XHTML enables you to write cleaner, well-structured code that leads to fewer errors and better compatibility across different browsers and devices.
In job interviews, expect to face a range of questions testing your understanding of XHTML – from the basic concepts to real-world applications and troubleshooting. This article compiles 15 common XHTML interview questions that you may encounter. Read on to learn the answers and boost your preparation.
1. What are the key differences between HTML and XHTML?
While HTML is focused on displaying information, XHTML aims to describe information as well. The key differences are
XHTML elements must be properly nested and closed.
Lowercase tag names are required in XHTML.
Attributes must be quoted in XHTML.
XHTML documents need one root element.
Empty elements like <br> must be closed in XHTML e.g. <br />
These strict syntax rules make XHTML more standardized and compatible across platforms
2. How can you ensure an XHTML document is valid?
To validate XHTML and check for errors, follow these practices:
Use the correct XHTML doctype declaration.
Properly nest tags and close all elements.
Check for proper use of lowercase tag and attribute names.
Quote all attribute values.
Use self-closing tags like <br /> for empty elements.
Validate frequently with tools like W3C Markup Validation Service.
3. What are the benefits of serving XHTML pages as XML rather than HTML?
When served as application/xhtml+xml, XHTML is treated as XML by web browsers. This ensures:
Proper parsing and handling of XHTML markup.
Ability to process XHTML using XML tools.
Leveraging XML features like namespaces.
Clear identification as an XML application vs HTML.
Overall, it respects the XML principles of stricter structure and syntax.
4. How do you handle special characters and symbols in XHTML?
In XHTML, special characters like < or & must be written with character entities like < and &. For other symbols, I refer to resources like W3Schools’ list of XHTML entities to find the correct codes.
For non-ASCII characters, I use numeric character references like © for the copyright symbol. If needed, I can also set the encoding to UTF-8 to allow direct use of special characters.
5. What are some key points for writing JavaScript in XHTML documents?
When adding JavaScript in XHTML:
Use CDATA sections like <script><![CDATA[JavaScript code]]></script> to avoid parsing errors from special characters.
Add type="text/javascript" attribute to the script tag.
Put script tags inside the <head> element.
Validate the XHTML document after adding scripts to catch errors.
Ensure graceful degradation if JavaScript is disabled on the user’s browser.
6. How is error handling different in XHTML compared to HTML?
XHTML uses XML’s strict error handling. If the document is not well-formed with proper nesting, closing tags etc., the browser will stop processing and show an error.
HTML is more forgiving – browsers try to recover from errors and make a best guess at rendering the faulty markup. This can lead to inconsistencies.
7. What are some key accessibility considerations for XHTML pages?
To make XHTML pages accessible:
Use semantic elements like <header>, <nav>, <main> etc.
Provide textual descriptions in alt attributes for images.
Ensure form inputs have associated <label> elements.
Make interactive elements keyboard accessible.
Use ARIA roles and attributes when needed.
Follow color contrast standards.
Allow font resizing by using EM/REM units.
8. How do you validate an XHTML document?
I validate XHTML using:
W3C Markup Validation Service – Allows file uploads, direct input or URL.
Browser Developer Tools – Highlight errors in the code.
Build Process Validation – Integrate a validator like grunt-html in the build pipeline.
Fragment Testing – Validate parts of a large document.
This catches issues so I can fix them early before deployment.
9. What is the purpose of the XML prolog in XHTML?
The XML prolog appears at the top of an XHTML document with the XML declaration like:
xml
<?xml version="1.0" encoding="UTF-8"?>
It specifies the XML version in use and the document’s character encoding. The prolog is optional but recommended in XHTML as it ensures proper interpretation of the character set.
10. How do you implement a clickable image link in XHTML?
Use CSS to absolutely position the submenu and toggle visibility on hover.
15. What are some key differences in developing for mobile vs desktop browsers with XHTML?
For mobile XHTML development:
Optimize design and content for smaller screens.
Ensure keyboard accessibility for devices without mice.
Check for mobile browser CSS and JavaScript support.
Reduce image sizes and HTTP requests.
Implement responsive design with media queries.
Validate for performance on slower network connections.
The constraints of mobile devices require additional testing and performance considerations.
Summary
XHTML is a pivotal skill for web developers today as it promotes good coding practices that lead to more robust, interoperable websites. Preparing answers to common XHTML interview questions demonstrates your understanding of web standards and ability to write semantic, valid markup.
Knowing how to explain your approach to writing, testing and maintaining XHTML documents also highlights your technical expertise in this field. With the responses provided in this article, you can now tackle XHTML interview questions confidently!
6 Answers 6 Sorted by:
Bugs in validation don’t make downloads take longer; in fact, the only thing that keeps it from being valid HTML 4 is some extra whitespace. 01 Transitional is the missing alt attribute).
The things that could increase download times are:
They might be bigger than 10×10 and need to be shrunk down.
Instead of cache-friendly CSS, presentational attributes are used, which won’t make a difference for this one time.
Since links inside other links have a border by default, border=0 might not be as “unnecessary” as you think (though it is still better to use CSS for this).
There is a space at either end. Thats 2 unnecessary bytes to download 😉
something.gif might not actually be pointing to a static picture on the filesystem.
Reduces the download time by about one round trip time. Since its quite small, 10 by 10, the overhead of base64 is not significant, I think.
This is because the code is very big, which makes it take longer to load or show.
The is using a relative path, so it might not download at all if you look at it in an email client.
XHTML Interview Questions and Answers
FAQ
What is the main goal of XHTML?
The primary goal of XHTML is to create a stricter way to develop websites consistently and expectantly. XHTML works by allowing you to write standard HTML using the strict guidelines of the XML format. It’s also worth considering that HTML should not be confused with HTML5 as they are different.
What is XHTML short answer?
XHTML (Extensible HyperText Markup Language) is a family of XML markup languages that mirror or extend versions of the widely used Hypertext Markup Language (HTML) Flexible framework requiring lenient HTML specific parser. Restrictive subset of XML which needs to be parsed with standard XML parsers.
Why is XHTML more strict than HTML?
XHTML was developed to make HTML more extensible and flexible to work with other data formats (such as XML). In addition, browsers ignore errors in HTML pages, and try to display the website even if it has some errors in the markup. So XHTML comes with a much stricter error handling.
What are HTML interview questions?
We’ve divided these questions into beginner, intermediate and advanced level HTML interview questions. 1. Define HTML. HTML stands for HyperText Markup Language. HTML is a standard text formatting language that creates and displays a variety of pages on the web. 2. What are the components of HTML?
Why is XHTML better than HTML?
All XHTML elements must always be closed. All XHTML elements must be written in lower case. Every XHTML document must have one root element. That is the reason behind its preferences over HTML because; most of the web pages contain bad HTML. 3) What is the difference between XHTML and HTML?
Which XML tags must be nested?
The xmlns attribute in is mandatory and must specify the xml namespace for the document. ,