Setup Java Environment Variable

What is Environment Variable???

Environment variables are the variables which decides the functionality of Command Prompt.

e.g. 

      If we talk about java, then if we don't setup the environment variable,then we have to run program by going in the bin directory which contains the java.exe and javac.exe file which are used for program compilation and running the program.

And moreover we have to paste the source code file in bin directory which creates our work more difficult. 

But if we setup the environment variable, then we can run our source code from any directory.

Here is the demo for HOW TO SETUP ENVIRONMENT VARIABLE FOR JAVA.........

If you have any query regarding this or anything else related to programming then feel free to contact us either by leaving comment here or just mail us at surinderrajpal[at]india.com

Ruby Programming Demo

Ruby , as described before this post, is most powerfull interpreted language.
Syntax used in Ruby is just like Perl, Lisp and SmallTalk which doesn't means that you have to learn these languages first. But you can start learning ruby if and only if you have some basic programming knowledge like control statements(e.g. looping), conditional statements(e.g. if else).
Now as you know what ruby language is and where it is used?
 So we start our practice by implementing our first program i.e. Printing "Hello World"

I have made a video for this Program tutorials.
Program is given below:-

"
puts "Hello World!!!"

"

Above program results in Printing Hello World!!! on the screen.
The tutorial is shown below so have a look over it...





For any query feel free to contact us by leaving your valuable comment on the post or on the video.....

RUBY Introduction

RUBY- AN INTERPRETED PROGRAMMING LANGUAGE

• Ruby is one of the most powerful programming language.
• It is object-oriented programming langauge.
• It is an interpreted language i.e. A little bit code conventions are there.
• Its the simplest one of all Object-Oriented languages.
• The code saved in file with the extension either .rb or .rbw
• All the facilty is provided in this like Window Programming, Console Programming.
• This is used on web also in combination with rails.
• RUBY ON RAILS which is one of the most powerful scripting language.
• Scripting languages are the languages which run directly i.e. no need to convert them first into machine-dependent code.So it is the fastest language.
• The code convention are similar to PERL, SMALL-TALK, LISP, ADA, EIFFEL.
• It is the language which is similar to HUMAN BODY i.e Simpler from outside Complex from inside.
• This is the language with balanced functional programming with impretive programming.
• Yukihiro “Matz” Matsumoto, Creator Of Ruby, often said that "he is trying to make Ruby Natural, but not simple.
• After its public release in 1995, It has drawn devoted coders world-wide.
• One more thing about ruby is its free of cost. That means anyone can be expert in this without paying anything.
• It also provide the facility of calculator i.e. We can any computation directly without writing any code.

Android Setup (Configuration )

Now we learned much that we can start doing practical, so now the problem is how to setup or configure Android on your PC.

Now the requirements are:-

1. Android SDK(Software Development Kit)
2. JDK (Java Development Kit )
3. Eclipse with ADT (Android Developer Tool) plug-in

After installing these three components you need to configure Android SDK Path for Eclipse.

To do so follow the steps explained in the document attached below. To view the document, click here

In this document, you will find following things:-

• Requirements
• Configuration Guide
• + Your First App Guide (App to print hello on screen )

Here you are going to place your first feet in Android Development, so wish you best of luck......

Keep enjoying.........

Activity In Android

As we provided the just intro about the main components of android, now we'll discuss these components in details. First component we discuss is ACTIVITY.

As we all know that activity is used to display the user interface just like in AWT or SWING in java. Interface is made in XML(eXtensible Markup Language).
Activity is an class provided by the android framework . which provide the facility to display the layout to the user. This class provide some callback methods to represent the different change of state of an activity.
To define an activity, we have to create a subclass of Activity Class and need to override its methods.
Different change of state of an activity are as follows:-

1. Active State
2. Visible State
3. Inactive / Invisible State

     1. Active State:-   An activity is in active state only when it has user focus and it is visible to user to handle       the life-cycle of the activity. 

Life-cycle of an active activity can be managed by onPause() and onResume() callback methods.

     2. Visible State:- An activity is in visible state when it appears to the user but doesn't have user focus.

Life-cycle of an visible activity can be manged by onStart() and onStop() callback methods.

     3. Inactive/Invisible State:- An activity is in Inactive/Invisible state when it doesn't have user focus and also doesn't appear to the user.

Life-cycle of an inactive state can be managed by onCreate() and onDistroy() callback methods.

Components of Android

Android has basically four components which it uses to manage all the applications.
These are as follows:-

1. Activity
2. Content Provider
3. Broadcast Reciever
4. Service
   

Here is just the overview of the components of Android.These components of android will be discussed in later posts.

1. Activity:- Activity is an visible component of android which is used to display the user interface to the user just like a frame in awt or swing.Interface is made using Xtensible Markup Language(XML).To use this, Activity class is provided by the android.Activity is full java based class.

2. Content Provider:-  This component provides the facility to share database between different applications.

e.g. As the contact detail is saved in contact application but we can use that information in other applications like Phone Dialer, Messaging, call, etc.

This facility is provided by Content Provider.

3. Broadcast Reciever:- This android component provides the facility to communicate between two or more applications. It is used by the application to broadcast its change of state to other applications.

e.g. Whenever we are listening music and a call is received at the same time, then in this situation music player is paused automatically and when the call is ended, Music player is resumed automatically.

This is done with the help of Broadcast Reciever.

4. Service:- Services are used to provide the facility for starting long running tasks which perform some operation in background and doesn't require much user interaction.

e.g. Downloading a file from network, playing some music in background,etc.

These tasks never interrupt in other applications.

These four components are the basic components which will discussed briefly in later posts with examples.