Java/C2/Creating-class/English-timed
From Script | Spoken-Tutorial
Revision as of 12:42, 30 March 2015 by Sandhya.np14 (Talk | contribs)
| Time | Narration |
| 00:02 | Welcome to the spoken tutorial on Creating classes. |
| 00:05 | In this tutorial, we will learn about: |
| 00:08 | * A class in real world |
| 00:10 | * A class in Java |
| 00:12 | * Structure of a Java class |
| 00:14 | * Syntax for a Java class |
| 00:16 | * And a simple example of Java class. |
| 00:19 | Here we are using:
|
| 00:30 | To follow this tutorial, you must know how to write, compile and run a simple Java program in Eclipse. |
| 00:37 | If not, please see the spoken-tutorial on these topics, available at spoken-tutorial.org. |
| 00:46 | Now let us see what is a class in real world. |
| 00:50 | Whatever we can see in this world are all objects. |
| 00:54 | And all the objects can be categorized into special groups. |
| 00:59 | Each group is termed as a class. |
| 01:02 | For example, human being is a class. |
| 01:05 | We are all different objects of this class. |
| 01:08 | We all have different properties like eyes, legs, hands etc. |
| 01:13 | Which are common to the human being class. |
| 01:15 | Seeing, eating, walking etc are behaviors that are common to the human being class. |
| 01:22 | Now let us see what is the class in Java? |
| 01:26 | A class is the blueprint from which individual objects are created. |
| 01:31 | Structure of a Java Class; A class defines: |
| 01:35 | * A set of properties called variables . |
| 01:37 | * And A set of behaviors called methods. |
| 01:40 | Now, let us see the syntax for declaring classes. |
| 01:44 | modifier – class -classname within curly brackets variable, constructor and method declarations. |
| 01:52 | We will learn about these in detail, in the coming tutorials. |
| 01:58 | Now, let us create a simple class using Eclipse. |
| 02:03 | I have already opened Eclipse. |
| 02:09 | Now let us create a Project. |
| 02:11 | So click on File, go to New and click on Java Project. |
| 02:20 | In the New Project Wizard, enter the Project name as ClassDemo with C and D in capital. |
| 02:34 | Then click on Finish. |
| 02:38 | We see that the Project ClassDemo is created. |
| 02:43 | We will now create a Java class name Student. |
| 02:47 | So, right click on ClassDemo, go to New and click on Class. |
| 02:56 | In the New Java Class wizard, type the Name as Student. |
| 03:03 | We can see that the modifier here is public. |
| 03:07 | This shows that the class is visible to all the classes everywhere. |
| 03:11 | If a class has no modifier which is the default, it is visible only within its own package. |
| 03:18 | We will learn about packages in the later tutorials. |
| 03:23 | Here I have selected public. |
| 03:26 | In the 'method stubs', select public static void main. |
| 03:31 | Then click on Finish. |
| 03:36 | We can see that the class named Student is created. |
| 03:40 | Now, let me remove the comments. |
| 03:51 | A Student class can contain properties like Name, Roll Number, Marks etc. |
| 03:57 | So, inside this class Student, let me declare two variables Roll Number and Name. |
| 04:04 | So, I will type int roll underscore number semicolon'. |
| 04:14 | String name semicolon. |
| 04:19 | So, I have declared two variables. |
| 04:22 | Now, a class also contains methods. |
| 04:25 | So, let me create a method named StudentDetail. |
| 04:30 | This method will give the detail of each student. |
| 04:34 | So let me type, void studentDetail then opening and closing brackets, curly brackets open. |
| 04:49 | Now, this method will give the roll number and name of the Student. |
| 04:53 | So, type System dot out dot println within brackets and double quotes The roll number is we can type it as number is, close the double quotes plus roll_number semicolon . |
| 05:23 | Next line, type: System dot out dot println within brackets and double quotes The name is plus name and semicolon. |
| 05:40 | Now, inside the main method we will type: System dot out dot println within brackets and double quotes We have created a class with two variables and 1 method. |
| 06:10 | Thus, We have created the class student. |
| 06:20 | Now, let me save the file by pressing Control and S keys simultaneously. |
| 06:26 | Let me Run the program by pressing Control and F11 keys simultaneously. |
| 06:33 | We get the output as : |
| 06:34 | We have created a class with 2 variables and 1 method , |
| 06:38 | just as we had typed in the main method. |
| 06:46 | Thus we have successfully created a class. |
| 06:50 | So, in this tutorial, we learnt about a class in java and how to create a class in java. |
| 06:59 | For self assessment, create a class named Employee with variables emp underscore number and emp underscore name . |
| 07:10 | And method printEmployee which displays the Employee information. |
| 07:16 | To know more about the spoken-tutorial project, |
| 07:19 | watch the video available at [1] |
| 07:22 | It summarizes the Spoken Tutorial project. |
| 07:25 | If you do not have good bandwidth, you can download and watch it. |
| 07:30 | The Spoken Tutorial project team: |
| 07:32 | Conducts workshops using spoken tutorials. |
| 07:35 | Gives certificates to those who pass an online test. |
| 07:38 | For more details, please write to contact@spoken-tutorial.org |
| 07:44 | Spoken Tutorial project is a part of the Talk to a Teacher project. |
| 07:48 | It is supported by the National Mission on Education through ICT, MHRD, Government of India |
| 07:55 | More information on this mission is available at
[2]. |
| 08:04 | Thus, we come to the end of this tutorial. |
| 08:07 | This is Arya Ratish from IIT Bomaby, signing off. Thanks for joining us. |
