Top 45 XML Interview Questions And Answers for 2021 [LATEST]

Comprehensive List Of Most Frequently Asked Basic and Advanced XML Interview Questions with Detailed Explanation and Code Examples:

XML is mainly preferred by the developers for designing, developing and maintaining interface. The reason for which most of them prefer XML over HTML is that XML allows you to define your own element.

This tutorial will cover all XML related topics with a detailed explanation for your easy understanding. Anyone from a beginner to an experienced person can well be prepared for an XML interview with this set of XML Interview Questions.

XML Interview Questions

Most Popular XML Interview Questions And Answers

Enlisted below are some of the most commonly asked XML interview questions that you must know before appearing for an XML interview.

Q #1) What does XML stands for?

Answer: XML stands for Extensible Markup Language.

Q #2) What is XML used for?

Answer: XML is a tool that is used to store and transfer data.

Q #3) Is XML format or content-driven?

Answer: XML is content-driven.

Q #4) Does XML support user-defined tags?

Answer: Yes, the users can create their own tags in XML.

Q #5) What is XML declaration tag?

Answer: <? XML version = “1.0” encoding = “UFT-8”? >

Q #6) Can XML be used for multimedia purpose?

Answer: Yes, XML can be used for multimedia purposes by using SVG and SMIL.

Q #7) What does SVG stand for and what is it used for?

Answer: SVG stands for Scalable Vector Graphics. It is an XML language that is used to display animations, images, graphics, and 2D from the XML code. Vector mathematical formulas are used here to render the content.

Q #8) What does SMIL stand for and what is it used for?

Answer: SMIL stands for Synchronized Multimedia Integration Language. It is an XML language that is used to integrate images, text, and other media for a presentation.

Q #9) What is the difference between XML and HTML?

Answer: 

XMLHTML
XML consists of user defined tags.HTML consists of pre-defined tags.
XML is used to store and transform data.HTML is used for designing a web page.
XML is content driven.HTML is format driven.
XML is case sensitive.HTML is not case sensitive.
XML requires end tag for well formatted document.HTML does not require an end tag.

Q #10) What are the benefits of XML?

Answer: The benefits of XML are as follows:

  • Simplicity: XML is simple to read and understand.
  • Availability: XML can be created using any text editor.
  • Flexibility: XML doesn’t have any fixed tags, hence user-defined tags can also be used.

Q #11) What importance does XSLT hold in XML?

Answer: XSLT stands for Extensible Style sheet Language Transformation. It is used to transform an XML document to HTML before it is displayed to any browser.

Q #12) What is XQuery?

Answer: XQuery is used to fetch data from the XML file, which is the SQL database.

Q #13) What is Xlink in XML?

Answer: Xlink used in XML files, are the standard way of creating hyperlinks in XML files.

Q #14) What is Xpointer in XML?

Answer: Xpointer in XML allows hyperlinks to point to more specific parts of the XML documents or files.

Q #15) What is XML signature/encryption?

Answer: It defines the processing rules and syntax for encrypting and creating digital signatures on XML.

Q #16) What is DTD in XML?

Answer: DTD stands for Document Type Definition, which describes a document written in XML. XML declaration syntax is defined in DTD. Naming convention rules of different types of elements are also defined in DTD.

Q #17) What is DOM? What is it used for?

Answer: DOM stands for the Document Object Model. It is an API, Application Programming Interface that allows navigation through objects. Documents are treated as objects. DOM documents are generated by the user or created by a parser.

Q #18) What is the main disadvantage of DOM?

Answer: The main disadvantage is that a large portion of memory is consumed by DOM.

Q #19) What does SOAP stand for?

Answer: SOAP is a Simple Object Access Protocol.

Q #20) What is the relation of SOAP with XML?

Answer: SOAP uses XML to define a protocol for the exchange of information in distributed computing environments.

Q #21) What are the three components in SOAP?

Answer: It consists of an envelope, a set of encoding rules, and a convention for representing remote procedure calls.

Q #22) What is XML parser function?

Answer: It is used to convert an XML file or document into the XML DOM object which is usually written in JavaScript.

Q #23) What is an XML schema?

Answer: XML schema provides definition of an XML document.

It comprises of:

  • Attributes and elements.
  • Child elements.
  • The data type of elements.
  • Order of elements and attributes.

Q #24) What is CDATA in XML?

Answer: CDATA stands for character data. Characters like ‘<’ and ‘>’ are not allowed in XML. CDATA starts with <! CDATA [“and end with”]>. CDATA is an unparsed character data that cannot be parsed by the XML parser.

Q #25) How are comments used in XML?

Answer: Comments are displayed as <!—comment–> . It is similar to HTML. It can be used for a single line or multiple lines.

Q #26) What is the usage of XML in development?

Answer: XML has multiple usages as shown below:

  • XML is used for flat files and databases.
  • It is used to store data and transport data on the Internet.
  • It can generate different dynamic data using style sheets.
  • XML is used to develop database-driven websites.
  • It is used to store data for eCommerce websites.

Q #27) What are the disadvantages of XML?

Answer: Disadvantages of XML include:

  • XML is just a text file if attributes and elements are not closed and defined properly.
  • Overlapping markup is not allowed.

Q #28) What do XML editors check?

Answer: The XML editors check are as follows:

  • XML against schema
  • XML Syntax color code
  • XML against DTD
  • XML standard open and close tags

Q #29) What is Diffgram in XML?

Answer: Diffgram is an XML format that is used to find the current and original versions of the XML document.

Q #30) What is XML Parser?

Answer: XML parser is a piece of software, which checks for a well-defined format and performs validation of document. It also allows us to read, create, and modify an existing XML document.

Q #31) How to connect XML with the database?

Answer: XML import and export modules are used to connect XML applications with databases. There has to be a 1:1 match between the field name of element type and the database table in DTD or XML schema. While in some cases little programming is required to establish the desired match.

Q #32) How to run an XML file?

Answer: XML is not a programming language. It cannot be run or executed. It can be viewed or displayed on the browser or using the XML editor.

Q #33) Describe XPath.

Answer: XPath can be described as follows:

  1. XPath is a W3C recommendation.
  2. It is the syntax for defining parts of an XML document.
  3. It uses path expressions to navigate in the XML documents.
  4. XPath contains a standard function library.
  5. XPath is a major element of the XSLT standard.
  6. It is used to navigate through attributes and elements in an XML document.

Q #34) Provide an example of XML.

Answer:

<? XML version=”1.0” encoding = “UTF-8”?>
<FurnitureStore>
<Furniture category=”Table”>
<Title lang=”en”> Sale for today</Title>
<Type> Laptop table</Type>
<Year>2008</Year>
<Price>500</Price>
</FurnitureStore>

Q #35) What are well-formed XML documents?

Answer: Well-formed XML documents have the following features:

  1. An XML document must have a root element.
  2. XML tags are case sensitive.
  3. XML elements should be properly nested.
  4. XML values should be properly quoted.
  5. XML tags should be closed properly.

Q #36) What are XML attributes? Explain with an example.

Answer: XML attribute values should always be quoted. Single or double quotes can be used in XML.

For example:

  • <Person degree = “PHD”>
  • <Person name = ‘Jacob’>

Q #37) Write a code for XML attribute and element.

Answer:

<Person location = “India”>
<Statename>Maharashtra</Statename>
<Cityname>Mumbai</Cityname>
</Person>
     <Person>
     <Location> India </Location>
     <Statename>Maharashtra</Statename>
     <Cityname>Mumbai</Cityname>
     </Person>

In the first element, location is an attribute. In last, location is an element. The user can choose the attribute or element.

Q #38) Can XML files be viewed in browsers?

Answer: Yes, the XML file can be viewed in all known browsers. They are not displayed as HTML pages.

Q #39) What is XML Httprequest? What are its advantages?

Answer: All modern browsers have a built-in XML Httprequest object to request for data from a server.

Its advantages are as follows:

  • Updating a web page without reloading the page.
  • Request data from a server
  • Receive data from a server after the page has been loaded.
  • Send data to a server in the background.

Q #40) Example of HttpRequest.

Answer:

var xhttp= newXML Httprequest();
Xhttp.onreadystatechange=function();
{ If this.readystate==4&& this.status==200)
		{ Action to be performed when document is ready;
Document.getelementbyID(“Demo”)
Innerhtml=xhttp.responseText;}};

Q #41) What is XML element?

Answer: The XML element contains start tag, end tag, and values.

For Example:

  • <City&gt; Pune </City>
  • <Price> 400.00 </Price>

XML element with no value is said to be empty like <element> </element>

Q #42) What are XML naming rules?

Answer: Naming rules are:

  • Element names must start with a letter or underscore.
  • Element names are case sensitive.
  • Element names cannot start with the letters XML.
  • Element names can contain letters, digits, hyphens, underscore, and periods.
  • Element names cannot contain spaces.

Q #43) What is SAX in XML?

Answer: SAX stands for Simple API for XML. It is a sequential access parser.

It provides a mechanism of reading data from an XML document. It is said to be an alternative to DOM. DOM operates on the documents as a whole, SAX parsers operate on each piece of the XML document sequentially.

SAX consumes less memory. It cannot be used to write an XML document.

Q #44) What is XSNL?

Answer: XSNL stands for XML Search Neutral Language. This language acts between the meta-search interface and the targeted system.

Q #45) What is the difference between a simple element and a complex element?

Answer: Simple elements cannot be left empty. It contains fewer attributes, child elements, etc. Simple elements are text-based elements. Complex elements can contain sub-elements, empty elements, etc. The complex element can hold multiple attributes and elements.

Conclusion

We have covered most commonly asked XML interview questions with answers for the beginner as well as experienced level interviews.

Always be prepared with the subject before any interview and answer the questions with confidence – Success will surely be yours.

All the best for your interview!!