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Last Updated: Jun 12, 2024

XML Interview Questions

Author Harsh
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13 Jun, 2024 @ 01:30 PM
Muskan Rathore
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Extensible Markup Language (XML) is a markup language that is comparable to HTML but does not have built-in tags. Instead, you create your own tags that are tailored to your requirements. In a format that can be kept, searched, and shared, this is a potent way to store data. Most crucially, because XML's basic format is standardized, the recipient can still parse the data if you exchange or transmit XML across systems or platforms, whether locally or via the internet.

The article consists of a total of 30 XML interview questions. They are divided into easy, medium, and hard level questions according to the difficulty level. So let’s get started.

XML Interview Questions

Easy Level XML Interview Questions

1. What do you mean by markup language?

Markup languages can be used to transport and store data in addition to presenting text in a variety of formats. With the use of this markup language, data formatting, layout, and style are codified. Tag describes this markup language.

2. Describe XML.

Considering XML interview questions this question is one of the important questions. Extensible Markup Language, also known as XML, was created to transmit, transfer, and store data. Although XML tags are not as predefined as HTML tags, we can define our own user tags to make things more straightforward. It focuses mostly on data storage rather than data display.

3. What are XML Namespaces, exactly?

In XML, element names are defined by the developer. When attempting to mix XML documents from multiple XML applications, there is a high change of element name conflicts. XML Namespaces allow you to avoid element name conflicts by using a prefix before element names.

4. Describe the XML Parser.

An XML document is converted into an XML DOM object that can be written in Javascript using an XML Parser.

XML Parser


5. Can I run XML code?

No, XML codes cannot be executed and cannot be used as a programming language. XML is simply used as a markup language, to represent data in a particular format.

6. What special characters are there in XML?

The five special characters used in XML are:

  • &lt; (<)
  • &amp; (&)
  • &gt; (>)
  • &quot; (")
  • &apos; (')

7. Describe XML Encoding.

Non-ASCII characters like French and Norwegian may be found in XML documents. To prevent mistakes, XML files must be saved as Unicode and use XML Encoding.

8. In XML, how do you comment?

In XML, you can use the following tag to comment out a line:

<! -- comment -->


<?xml version = "1.0" encoding = "UTF-8" ?>
<!--This is a comment -->
<!-- Another comment -->

9. What is coding in XML?

A markup language and file format for storing, sending, and recreating arbitrary data is called Extensible Markup Language (XML). It outlines a set of guidelines for document encoding in a way that is both machine and human-readable.

10. Is XML a form of programming?

A programming language is not XML. However, it is used to annotate data using tags, which understand that data, as a markup language.

Medium Level XML Interview Questions

11. Describe the XML Document Object Model.

This is a very important question considering XML interview questions. The root of a document tree is an XML Document object, which represents the whole XML document. It contains its own characteristics and grants access to the complete XML document, allowing you to programmatically read, manipulate and modify an XML document.

12. What characteristics does XML have?

These are XML's primary features:

• Very simple to understand and use

• Since XML files are text files, a specific editor is not necessary.

• There are few and insignificant XML syntax rules.

• It describes the structural rules of tags and is expandable.

13. What benefits does an XML DOM (Document Object Model) offer?

Benefits of XML DOM

  • XML DOM is language and platform independent.
  • XML DOM is traversable - Information in XML DOM is organized in a hierarchy, developers can move across the hierarchy in search of specific information.
  • The XML DOM is modifiable - It is dynamic, allowing the developer to add, update, move, or remove nodes at any point along the tree.

14. What are the fundamental guidelines for developing XML?

These are the fundamental guidelines for writing XML:

• A root element should be present in all XML documents.

• Make sure all tags are closed.

• Case matters when using XML tags.

• All tags must be properly nested.

• Spaces are not permitted in tag names.

• Quotes should surround the attribute value.

• The white space should be maintained.

15. Describe an XML element.

XML elements can be thought of as XML building blocks. Elements can act as containers for text, elements, attributes, media objects, or any combination of these.

Each XML document has one or more elements, the scope of which is defined by start and end tags, or by an empty-element tag for empty elements.

It may include:

• Subordinate elements to the primary element

• A Qualifier

• Text

16. What is an XML Schema, exactly?

A definition of an XML document is provided by an XML schema, which includes the following:

• Components and qualities

• Child elements for components

• Child element placement

• Elements and attributes' data types

17. How do you define a well-formed XML document?

A properly formatted XML document must adhere to the following guidelines:

• An end tag should follow every start tag.

• Case matters when using XML tags.

• Empty tags must be present for a forward slash to be used.

• Each tag must be correctly nested.


18. Can XML take the place of HTML?

No, XML doesn't take the role of HTML. In addition to being used for data processing and storage, XML offers an alternate method for defining one's own set of markup components which in no way handles HTML responsibilities.


19. What advantages does XML offer?

A few advantages of XML

• Easy to read and comprehend

• Any text editor can be used to create XML.

• Flexibility—There are no fixed tags

• Self-deprecating

• Can incorporate many data types

20. What drawbacks does XML have?

The following are XML's drawbacks:

• If elements and attributes are not defined properly, XML will just be a text file.

• Cross-referenced markup is not allowed.

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Hard Level XML Interview Questions

21. Is XML similar to HTML?

Extensible Markup Language (XML) is a markup language that is comparable to HTML but does not have built-in tags. Instead, you create your own tags that are tailored to your requirements. In a format that can be kept, searched, and shared, this is a potent way to store data.

22. Why does communication use XML?

In paper format, the XML data contains self-sufficient information. It is therefore platform-independent. Its use makes it simple to send a document over HTTP from one site to another. More specifically, XML is utilized for information sharing and communication across various applications.

23. Is XML an Internet protocol?

Not at all. XML is occasionally referred to as a communication protocol. A communication protocol is a predetermined collection of characters that allows data bytes to be transferred between two systems. XML is the foundation language for communication protocols such as SOAP and XMPP. It is the message format used by the Asynchronous JavaScript and XML (AJAX) programming approach.

24. Describe DTD.

Document Type Definition, or DTD, is an acronym for the definition of the legal building pieces of an XML document. It specifies the components and attributes that make up the XML document structure.

25. Describe XQuery.

The purpose of XQuery is to query XML data, which is like SQL for database tables. Data is extracted from the XML file using XQuery.

26. What are XPointer and XLink?

The industry-standard method for adding hyperlinks to XML files is called XLink. These hyperlinks can now point to more precise locations within the XML file or document thanks to Xpointer.

27. Complex Element: What is it?

An XML element that incorporates other elements and/or attributes is known as a complex element.

Complex elements are classified into four types:

  • Empty elements
  • Elements that contain only other elements
  • Elements that contain only text
  • Elements that contain both other elements and text

28. What exactly is Simple Element?

A simple element is an XML element that contains only text. It cannot contain any other elements or attributes. A simple element can’t be empty.

29. What kinds of XML Parsers are there?

Non-Validating and Validating Parsers are the two different categories of parsers. The name itself implies that Non-Validating will not do any XML validation while Validating parser will perform XML validation using DTD.

30. How do XML Signatures work?

XML Signature defines an XML syntax for digital signatures and is defined in the W3C recommendation XML Signature Syntax and Processing.

  • A detached signature is one that is located outside of the document. 
  • Enveloping signatures are those that are contained inside an XML document.


In this article, we have extensively discussed XML Interview Questions. These XML interview questions are very important considering new jobs requirements. We hope that this blog has helped you enhance your knowledge about XML.

After reading XML interview questions, are you feeling excited to read/explore more articles on this topic? Don't worry; Coding Ninjas has you covered. You can visit any of the mentioned link to learn more GWT XMLJSON vs XML - Differences and SimilaritiesAJAX - The XMLHttpRequest ObjectJSP - XML Data.


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