Java Script An Introduction By HWA

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Java ScriptAn Introduction
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What is Java Script?

• Java Script is one of the most pervasive
  languages found on the internet and World Wide
  Web. 
• Java Script is useful in making web pages more
  interactive.
• The pages can be made to react to the actions of
  the users in the form of special effects, both
  visual and otherwise.

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Introduction to Java Script

• Java Script began as a joint effort between
  Netscape Communications Corporation and Sun
  Microsystems beginning in the year 1995. 
• Java Script is an object-based, client-side
  scripting language that can be used to make web
  pages more dynamic.

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Object-based

• Java Script can make use of items called objects.
  
• The use of objects is different in Java Script
  because, here the objects are not class based.
• There is no distinction between classes and
  instances.

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Client-side

• Java Script is run on the client systems.
• Here, Java Script is run on the web browser
  rather than on the web server which is serving a
  page from the website.

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Scripting Language

• A Scripting Language is very different from the
  conventional programming languages.
• One of the main differences is that a scripting
  language does not require a compiler to run the
  program.
• In a scripting language the code is interpreted
  as it is being loaded. This saves the time of the
  client.

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Script Tags

• Script Tags are used to trigger the beginning and
  ending of a scripting language in a HTML
  document.
• In the most basic forms, these scripting tags are
  seen as just any other HTML tags.

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External Scripts

• External Script file is a text file that
  contains Java Script code.
• This is external script is used to run the code
  on a multiple pages.
• This is a time saving act for the client.

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Variables

• A Variable is used to hold value. A variables
  actual value can be altered at any point in time.
  
• Variables are used when the coder does not know
  the kind of values that will be used in the
  script.

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Variables Contd

• Variables can save time in writing and updating
  the scripts.
• Variables include data types such as null value,
  number values, Boolean values, string values,
  etc.

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Functions

• A Function can be defined as smaller script
  within a larger script.
• Functions are particularly useful for performing
  small tasks or a series of tasks.

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Functions Contd

• Functions are useful in dividing the whole script
  into smaller parts so that each task is handled.
• This makes it easier to run the whole script and
  debug it quickly and easily

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• For more details on Java Script visit our
  websites at http//www.helpwithassignment.com/Java
  -Script-Programming-Assignment-Help 

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