Hsc IT Chap 3. Advanced javascript-1.pdf

Introduction
• There is variety of scripting languages used to develop dynamic
websites.
• JavaScript is an interpreted scripting language.
• An interpreted language is a type of programming language that executes its
instructions directly and freely without compiling machine language
instructions in precious program.
• The programs in this language are called scripts.

Introduction
• Program is a set of instructions used to produce
various kinds of outputs.
• JavaScript was initially created to "make webpages alive".

Features of JavaScript :
• JavaScript is light weight scripting language because it does
not support all features of object oriented programming languages.
• No need of special software to run JavaScript programs
• JavaScript is object oriented scripting language and it
supports event based programming facility. It is case sensitive
language.
• JavaScript helps the browser to perform input validation
without wasting the user's time by the Web server access.

Features of JavaScript :
• It can handle date and time very effectively.
• Most of the JavaScript control statements syntax is same
as syntax of control statements in other programming languages.
• An important part of JavaScript is the ability to create
new functions within scripts. Declare a function in JavaScript
using function keyword.
• Software that can run on any hardware platform (PC,
Mac, SunSparc etc.) or software platform (Windows, Linux, Mac OS
etc.) is called as platform independent software.
• JavaScript is platform independent scripting language. Any
JavaScript-enabled browser can understand and interpreted
JavaScript code. Due to different features, JavaScript is known as
universal client side scripting language.

There are two types of scripting
Client-side Scripting : In this type, the script resides on
client computer (browser) and that can run on the client.
Basically, these types of scripts are placed inside an
HTML document.
Server-side Scripting : In this type, the script resides on
web server. To execute the script it must be activated by
client then it is executed on web server.

Server-side Scripting Client-side Scripting
Server-side scripting is used at the
backend, where the source code is
not visible or hidden at the client side
(browser).
On the other hand, client side scripting is
used at the frontend which users can see
from the browser
Server-side scripting is more secure. Client-side scripting is less secure than server
side.
programming languages such as PHP, ASP.net,
Ruby, ColdFusion, Python, C# etc. are server
side scripting languages.
The client-side scripting language involves
languages such as HTML5, JavaScript etc.
Server-side scripting is useful in customizing
the web pages and implements
the dynamic changes in the websites.
The clientside scripts are generally used
for validation purpose and effectively minimize the
load to the server.
Special software (web server software) is
required to execute server-side script
Whereas client side scripts requires web
browser as an interface.

11th Standard Revision
1. Insertion of JavaScript in HTML
2. Variables
3. Data Types
4. Operators
a. Arithmetic operators (+,-,/,*,%)
b. Assignment Operators (=)
c. Relational Operators (<,>,<=,>=,!=,==)
5. Decision Making Statements
6. functions

Switch Case statement
Click to add text
• The switch statement test the value of given
expression against a list of case values and when
match is found, a block of statement associated
with that case is executed.
• JavaScript has a built–in multiway decision statement
known as Switch.
• There should not be duplicity between the cases.

Click to add text
• The default statement is not mandatory.
• The value for the case must be similar data type as the
variable in switch.

Click to add text
Click to add text
• Syntax :
• switch(expression)
• {
• case value1:
• statement block 1;
• break;
• case value2:
• statement block 2;
• break;
• …………....
• case value n:
• statement block n;
• break;
• default:
• statement block ;
• }

Click to add text
Click to add text
Output :

Looping Statement
Click to add text
• Iteration refers to the execution of statement or a group of
statements of code for a fixed number of times or till the
condition is satisfied.
• While creating programming logic, we need to execute
some statements repeatedly.
• The condition should be Boolean condition.

Some commonly used JavaScript
looping statements are:
1. For…….loop
2. While...loop
Click to add text
Click to add text

1. for…….loop
Click to add text
• Benefit of for-loop is that it combines initialization, condition and
loop iteration (increment or decrement) in single statement.
Click to add text
• This loop executes statements as long as condition becomes true,
control comes out from the loop when condition becomes false.

• Initialization is assigning initial value to the variable, which
executes only once, and then the condition is checked.
Syntax :
for(initialization; condition; iteration)
{
statement block;
}
• Loop will execute statements in statement block till the
condition is true.
• When condition becomes false control is transferred out of
the loop and it will execute remaining program.

• Iteration means increment or decrement value of
a running variable.

Example :
Click to add text
Click to add text

2. While…..loop
Click to add text
• As soon as condition becomes false control comes out of
the loop.
Click to add text
• This loop executes statements as long as the condition is
true.

• The statement within the loop may be a single line or a block of
statements.
Syntax:
initialization;
while(condition)
{
statement block;
}
• If the statement within loop is a single line then the curly parenthesis
is optional.
• Here loop will be executed repeatedly as long as the condition is true.

• Note that if condition always true then loop would be
executed infinitely so after some execution condition
becomes false.
Example :

Program for loop :
Click to add text
Click to add text
Output :

Break and continue statements
Click to add text
• When keyword break is encountered inside the
loop, control automatically passes to the next
statement after the loop.
• Break statement is used to jump out of loop. It is used to
make an early exit from a loop.
• Sometimes in looping it may be necessary to skip
statement block and take the control at the beginning for
next iteration
• This is done by using ‘continue’ statement in JavaScript.

Click to add text
Click to add text
Program :

Click to add text
Click to add text
Output:

Objects in JavaScript
Click to add text
• A JavaScript object is an entity having state (properties) and
behavior (methods).
• JavaScript is an object based scripting language. Almost
everything is an object in JavaScript.
• An object can group data together with functions needed
to manipulate it.
• Look around you, you will find many examples of real
world objects.
• Such as table, board, television, bicycle, shop, bus, car,
monitor etc.

• Take an example of car object. It has properties
like name, model, weight, color etc. and methods
like start, stop etc.
• All these tangible things are known as objects.
• All cars have same methods but perform differently.
• All cars have same properties but contain different values
from car to car.

• JavaScript supports 2 types of objects built-in
objects and user defined objects.
• Properties and methods of object's are accessed with '.'
operator.

2. JavaScript gives facility to create user defined
objects as per user requirements. The ‘new’ keyword
is used to create new object in JavaScript.
1. Built in objects such as Math, String, Array, Date etc.
e.g. d= new Date(); // ‘d’ is new instance created for
Date object

DOM (Document Object Model) :
• It defines logical structure of document.
• When HTML document is loaded into a web browser, it
becomes a document object.
• The way in which HTML document content is accessed
and modified is called as Document Object Model.
• It is programming interface for HTML and XML (Extensible
Markup Language) documents.

DOM (Document Object Model) :
According to W3C :
• The standardization of DOM was founded by W3C (World Wide
Web Consortium) which works for standardization of web
technologies.
• "The W3C Document Object Model (DOM) is a platform and
language-neutral interface that allows programs and scripts to
dynamically access and update the content, structure, and style of
a document."

Following diagram shows hierarchy of
DOM object:

Following are some of the
predefined methods and
properties for DOM object.

The innerHTML Property
• The innerHTML property is useful for getting html
element and changing its content.
• The innerHTML property can be used to get or change any
HTML element, including and .

Window Object :
• At the very top of the object hierarchy is the window
object.
• It represents an open window in a browser
• Window object is parent object of all other objects
• An object of window is created automatically by the
browser

Following table shows some of the methods
and properties for window object.

JavaScript Event
• In previous year we studied different keyboard events
(onKeypress, onKeydown, onkeyup) and mouse events
(onClick, onMousemove, onMouseout, onMouseover).
• Events are actions done by the user or an
application that occurs on the webpage.
• Similarly there are some more events used with form
objects.

Input and other object Events:

JavaScript Built-in Objects
• These built-in objects are available regardless of window
content and operates independently of whatever page
browser has loaded.
• JavaScript has several built-in or core language
objects.
• These objects provide different properties and methods
that are useful while creating live web pages.

String Object :
• String object is used to store and manipulate text.
• String is used to store zero or more characters of
text within single or double quotes

String Object :
• String object is used to store and manipulate text.
Example :
var str="Information Technology";
document.write ("length of string is :-" + str.length);
document.write ("Substring is :-" + str.substr (12,10));

Math Object :
• You do not need to create the Math object before using
it.
• The built-in Math object includes mathematical
constants and functions.

Following table contains list of math object methods: e.g. var
x=56.899; alert(Math.ceil(x));

Date Object :
• The date object is used to create date and time values.
• It is created using new keyword.
• There are different ways to create new date object.
1. var currentdate=new Date();
2. var currentdate=new Date(milliseconds);
3. var currentdate=new Date(dateString);
4. var currentdate=new Date(year, month, day, hours, minute, seconds, milliseconds);

Days Numbering in JavaScript
• 0 - Sunday
• 1 - Monday
• 2 - Tuesday
• 3 - Wednesday
• 4 - Thursday
• 5 - Friday
• 6 - Saturday,

Months Numbering in JavaScript
• 0 - January
• 1 - February
• 2 - March
• 3 - April
• 4 - May
• 5 - June
• 6 - July
• 7 - August
• 8 - September
• 9 – October
• 10 - November
• 11 - December

Time Numbering in JavaScript
• Hours --> 0-23
• Minutes --> 0-59
• Seconds --> 0-59
• Milliseconds --> 0-999

Array Object :
• An array is an object that can store a collection of items.
• JavaScript arrays are used to store multiple values in single
variable.
• An array is a special variable which can hold more than one value
at a time.
• Arrays become really useful when you need to store large
amounts of data of the same type

Array Object :
• You can create an array in JavaScript as given below.
• var days=["Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
"Saturday", "Sunday"];
OR
• var fruits=new Array("Monday", "Tuesday", "Wednesday",
"Thursday", "Friday", "Saturday", "Sunday");
• You can access and set the items in an array by referring to its
indexnumber and the index of the first element of an array is zero.

Array Object :
• arrayname[0] is the first element, arrayname[1] is second element
and so on.
• e.g. var fruitname=fruits[0];
document.getElementById("demo").inner HTML=fruits[1];

Validation program in JavaScript :

output :
Note : islnteger() is supported by version Mozilla Firefox 16 and
higher.

Hsc IT Chap 3. Advanced javascript-1.pdf

Recommended

More Related Content

What's hot (20)

Similar to Hsc IT Chap 3. Advanced javascript-1.pdf (20)

More from AAFREEN SHAIKH (20)

Recently uploaded (20)

Hsc IT Chap 3. Advanced javascript-1.pdf