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| XML INTERVIEW QUESTIONS |
1) What is
Extensible Markup Language (XML).
XML is a simple and flexible
markup language in the text format. Nowadays, it is widely used to exchange a
large variety of data over the Internet. XML consists of data as text in
well-defined customized layouts by using self-defining tags. These user-defined
tags are user friendly because they contain the name given by the user and make
the information easily understandable to a user. These user-friendly features
made XML to be widely used as a standard data-interchange format. The World
Wide Web Consortium (W3C) frequently develops new standard for XML usage by
different software vendors and solution providers. XML plays a very significant
role with respect to .NET Framework 4.0. .NET Framework 4.0 provides us with a
namespace called System.Xml, which includes classes that are used to work with
XML.
2)What is the
version information in XML?
"Version" tag
shows which version of XML is used.
3. If XML does not
have closing tag will it work?
No, every tag in XML, which
is opened, should have a closing tag.
4. Is XML case
sensitive?
Yes, XML is case sensitive.
5. Explain the
difference between XML and HTML.
XML describes data while HTML describes how
the data should be displayed. Therefore, HTML is about displaying information
while XML is about describing information.
XML supports user-defined tags while HTML
provides pre-defined tags.
XML is a case-sensitive language while HTML
language is not case-sensitive.
In XML, all tags must be closed; while in
HTML, it is not necessary to close each tag.
6)The XML
preserves white spaces. Is it true?
Yes, it is true.
7) Explain the XML
elements.
The elements are the central
units of an XML document that explain and identify data. The elements are
represented by the tags. You can also make your own tags, which make XML a
user-friendly language. By creating custom meaningful elements, you can improve
readability of the document. XML elements can be nested and the nested elements
are known as child elements.
8)Using XSLT, how
would you extract the value of a specific attribute from an element in an XML
document?
The components necessary for
the above mentioned operation are as follows:
The template element - Matches the correct XML
element.
The value-of element - Selects the attribute
value.
The optional apply-templates element - Allows
continuous processing of the document
9)Which classes
are supported to make an XML DOM?
The following are the
different classes in the System.Xml namespace that make up the XML DOM:
The XmlNode class
The XmlDocument Class
The XmlElement Class
The XmlAttribute Class
The XmlText class
The XmlComment class
The XmlNodeList Class
10)Which class is
used to encode and decode XML names and contains different methods to convert
between CLR types and XSD types.
The XmlConvert Class.
11)What is the
DTD?
The DTD is Document Type
Definition that describes the formation of the content of an XML document. The
DTD manages the data to store in a consistent format. It defines the XML
elements and attributes about how they should be present in XML documents and
what relation they should have with other elements and attributes. The DTD also
allows you to mention whether an XML element is optional or not. If the XML
documents are not according to the DTD rules, they are not considered valid.
12)Is it true that
the XML's goal is to replace HTML?
No, it is not true. Both are
necessary in their respective fields.
13)What is XSLT?
XSLT is Extensible
Stylesheet Language Transformations that is a part of XML, which is a mechanism
to transform an XML document into another XML or HTML document.
14)The XML
elements cannot be empty. Is it true?
No, it is not true.
15) Describe the
role that XSL can play while dynamically generating HTML pages from a
relational database.
The SQLXML 3.0 and advanced
versions provide the facility of mapping the SQL queries output with XSLT
templates. It uses XSLT to present the records that are retrieved from
databases on Web pages (HTML pages).
An application can use XSLT
to modify the output that is retrieved from data sources and display the output
by XSL templates. The XSLT displays data without affecting the database query
and the code of application.
16)What are the
advantages of DOM?
DOM
stores the entire XML document into memory before processing. Therefore, the
XML structure can be easily modified and values can be added, changed, and
removed.
DOM enables to traverse the XML structure
in any direction. It means that you can access any node of the XML structure by
traversing through the XML structure.
18)Which
namespaces in .NET are used for XML?
The System.xml.dll is the
real physical file, which contains the XML implementation. Some of the other
namespaces that allow .NET to use XML are as follows:
System.Xml
System.Xml.Schema
System.Xml.XPath
System.Xml.Xsl
19)Explain the
XmlReader class.
The XmlReader class is used
to read XML data in a fast, forward-only, and non-cached manner.
To work with XmlReader class
in .NET, you need to import the following namespace:
In C#:
using System.Xml;
In VB:
Imports System.Xml
20)Explain
different types of XML Application Programming Interface (API).
The following are two main
types of XML parsers:
Tree-based API - Compiles an XML document
into a tree structure and loads it into memory. You can traverse and change the
tree structure. The DOM is an example of a tree-based API.
Event-based API - Provides the report to an
application about the parsing events by a set of built-in callback functions.
An example of the event-based API is SAX.
21)Describe the
XmlWriter class.
The XmlWriter class is used
to write XML to a stream, a file, or a Textwriter object. This class works in a
forward-only, non-cached manner. You can configure the XmlWriter object up to a
large extent. With this object, you can specify a few things, such as whether
to indent content or not, the amount to indent, what quote character to use in
attribute values, and whether or not namespaces are supported.
22)What is XPath?
XPath stands for XML Path.
It is a language used to access different parts of an XML document, such as
elements and attributes.
23)What is an XML
attribute?
An XML attribute contains
additional information regarding that particular element. The XML attributes
use the name-value pair. For example, the element student has an attribute
called id and the value of this attribute is set to s01, as shown in the
following code snippet:
<Student
ID="s01">
...
</Student>
24)What is XML
DOM?
The DOM stands for Document
Object Model, which describes the logical formation of documents and provides
the way to access and manipulate a document. It supplies an Application
Programming Interface (API) to XML documents. It is built around the
object-oriented design; therefore, it is known as DOM. The DOM model considers
an XML document as a composition of objects and every object consists of
properties and behaviors that can be manipulated by the DOM methods. The DOM
allows creating and building XML documents, navigating the structure of
documents, and managing the elements and their data. You can use the DOM
methods and objects with any language, such as C#, VB, JavaScript, and VBScript.
25)Which classes
are supported to make an XML DOM?
The following are the
different classes in the System.Xml namespace that make up the XML DOM:
The XmlNode class
The XmlDocument Class
The XmlElement Class
The XmlAttribute Class
The XmlText class
The XmlComment class
The XmlNodeList Class