XML Basics For Beginners in Short

Why Study XML?
- It is important to have a good understanding of XML.
What is XML?
- Xml stands for extensible markup language.
- Xml designed to store and transport data.
- XML doesn’t do anything. It is just information wrapped in tags.
Difference between XML and HTML:
- XML was designed to carry data – with focus on what data is and HTML was designed to display data with focus on how data looks.
- XML tags are not predefined like HTML tags are:
  - XML language has no predefined tags.
  - With XML, the author must define both the tags and the document structure.
XML Simplifies Things like:-
- Data Sharing:-
  - Exchanging data between incompatible systems is a time-consuming task for web developers. Large amounts of data must be converted, and incompatible data is often lost.
  - XML stores data in plain text format. This provides a software- and hardware-independent way of sharing data.
- Data transport:-
  - XML stores data in plain text format. This provides a software- and hardware-independent way of storing and transporting data.
- Platform changes:-
  - With XML, it is easier to expand or upgrade to new operating systems, applications, or new browsers, without losing data.
- Data availability :-
  - XML also makes it available to all kinds of reading machines like computers, voice machines, peoples, news feeds, etc.
XML Separates Data From Presentation:-
- XML doesn’t know how the data should be displayed.
- Same XML data can be used in many different presentation scenarios.

XML Syntax Rules:-

<root>
    <child>
        <subchild>...</subchild>
    </child>
</root>

XML Prolog:-

    <?xml  version= "1.0" encoding="UTF-8"?>

XML prolog is optional.

XML Rules:-

All XML elements must have a closing tag.
XML elements must be properly nested.
XML tags are case sensitive.
XML elements must start with a letter or underscore but cannot start with letters xml.
XML elements can contain letters, digits, underscores, hyphens, and periods but cannot contain spaces.
XML attributes values must always be quoted ( either single or double quotes).

There are 5 pre-defined entity references in XML.

Entity	Char
<	<
>	>
&	&
'	'
"	"

Comments in XML
- <!—Comments -->
- Two dashes (--) in the middle of a comment are not allowed.
XML stores a new line as LF.
White space is preserved in XML.
- <TAG> Hello world </TAG>
Self-closing tag are allowed in empty elements.
- <element /> OR <element>...</element>

How To Handle Name Conflicts:-

If multiple XML fragments are added together, there would be a name conflict.
Name conflicts in xml can be easily avoided by using a name prefix.
- <h:name>…</h:name> and <p:name>…</p:name>

XML Namespaces:-

A Namespace is a set of unique names. Namespace is a mechanism by which element and attribute name can be assigned to a group.
When using prefixes in XML, a namespace for the prefix must be defined.
- It is defined by xmlns attribute in the start tag of an element.
- Namespace declaration has the following syntax:
```
<s:tag  xmlns:s="http://fit-coder.blogspot.com/p/names">
    <s:name> …</s:name>
</s:tag>
```

XML Parser:-

XML parser is a software library or a package that provides interface for client applications to work with XML documents.
It checks for proper format of the XML document and may also validate the XML documents.
The goal of a parser is to transform XML into a readable code.

Parsing a Text String :-

<html>
<head>
    <script>
    var str, parser, doc;
    str ="<store><chips>"+               //Text string is defined
         "<name> Haldiram </name>"+
         "<flavor> chili </flavor>"+
         "</chips></store>";
   
         //DOMParser() is an class to create new parser object.
         parser = new DOMParser();

         //parser create a new XML DOM object using the str string.
         doc = parser.parseFromString(str, “text / xml");
         document.getElementById(“demo").innerHTML = doc.getElementsByTagName(“name")[0].childNodes[0].nodeValue;
    </script>
</head>
<body>
    <h1 id="demo"></h1>
</body>
</html>

If you want to read the Question that are asked in interview, You can download the app InterQue,that Have many questions.

Cpp Question : Calculating Price of Eggs

Diary Farm sells organic brown eggs to local customers. They charge Rs 22.50 for a dozen for eggs, or rs 2.10 for individual effs that are not part of a dozen. Write a C++ Program a user for the number of eggs in the order and the displays the amount owned with a full explanation. For Example, typical output might be " You ordered 27 eggs. that's 2 dozens at rs 2.50 per dozen and 3 loose eggs at rs 2.10 each for a total of rs 51.30". The program must iterate until zero is entered for the number of eggs. Code: #include<iostream> using namespace std; int main(void) { int n; float price=0; int r=0,q; char ch; do { cout<<"\nEnter Numbe of eggs OR zero (0) to exit :"; cin>>n; if(n<0) { cout<<"Incorect Value"; } else if(n==0) { exit(0); } else { q=n/12; price+=q*22.50; r=n%12; ...

FitCoder

Search This Blog

XML Basics For Beginners in Short

Labels

Comments

Post a Comment

Popular posts from this blog

Cpp Question : Calculating Price of Eggs

XML : AJAX Tutorial For Beginners