Difference between revisions of "Java/C2/Creating-class/English-timed"

|  Welcome to the spoken tutorial on '''Creating classes'''.

|  In this tutorial, we will learn about:

|* A '''class''' in real world

|* A '''class''' in Java

|* Structure of a '''Java class'''  

|* Syntax for a''' Java class'''

|* And a simple example of '''Java class'''.

| Here we are using:

| To follow this tutorial, you must know how to write, compile and '''run''' a simple Java program in '''Eclipse'''.

|If not, please see the spoken-tutorial on these topics, available at '''spoken-tutorial.org'''.

|And all the objects can be categorized into special groups.

|Each group is termed as a '''class'''.

|For example, human being is a '''class'''.

|We are all different objects of this '''class'''.

|Now let us see what is the '''class''' in '''Java'''?

| A''' class '''is the blueprint from which individual objects are created.

| Structure of a '''Java Class'''; A '''class''' defines:

|* A set of properties called '''variables '''.

|* And A set of behaviors called '''methods.'''

|  Now, let us see the syntax for declaring '''class'''es.

|'''modifier – class -classname''' within  curly brackets '''variable, constructor''' and '''method''' declarations.

|We will learn about these in detail, in the coming tutorials.

|Now, let us create a simple '''class ''' using '''Eclipse'''.

|I have already opened '''Eclipse'''.

|So click on '''File,''' go to '''New ''' and click on '''Java Project.'''

| In the '''New Project''' Wizard, enter the '''Project name ''' as '''ClassDemo''' with C and D in capital.

| We will now create a '''Java class''' name '''Student'''.

|So, right click on''' ClassDemo''', go to''' New''' and click on '''Class'''.

|In the '''New Java Class''' wizard, type the '''Name''' as '''Student.'''

|This shows that the '''class''' is visible to all the classes everywhere.

|If a '''class''' has no '''modifier''' which is the '''default''', it is visible only within its own '''package.'''

| Here I have selected '''public.'''

|In the 'method stubs', select '''public static void main.'''

|We can see that the '''class''' named '''Student''' is created.

|So, inside this '''class Student''', let me declare two '''variables''' '''Roll Number''' and '''Name'''.

|So, I will type '''int roll''' underscore '''number''' semicolon'.

|  '''String name''' semicolon.  

|So, I have declared two '''variables.'''

|Now, a '''class''' also contains '''methods.'''

|So, let me create a '''method''' named '''StudentDetail.'''

|This '''method''' will give the detail of each student.

|So let me type, '''void studentDetail''' then opening and closing brackets, curly brackets open.

|Now, this '''method''' will give the roll number and name of the Student.

|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 .

|Next line, type: '''System''' dot '''out''' dot '''println''' within brackets and double quotes '''The name is''' plus '''name''' and semicolon.

|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.'''

|Thus, We have created  the '''class''' '''student'''.

|Now, let me '''save''' the file by pressing '''Control''' and '''S''' keys simultaneously.

|Let me '''Run''' the program by pressing '''Control''' and '''F11''' keys simultaneously.

|'''We have created a class with 2 variables and 1 method ''',

|just as we had typed in the '''main method'''.

| So, in this tutorial, we learnt about a '''class''' in java and how to create a '''class''' in java.

| For self assessment, create a '''class''' named '''Employee''' with variables '''emp''' underscore '''number''' and '''emp''' underscore '''name''' .

|And '''method''' '''printEmployee''' which displays the '''Employee''' information.

|  To know more about the spoken-tutorial project,

|  watch the video available at [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial]

| It summarizes the Spoken Tutorial project.

| If you do not have good bandwidth, you can download and watch it.

| The Spoken Tutorial project team:

| Conducts workshops using spoken tutorials.

|Gives certificates to those who pass an online test.

| For more details, please write to contact@spoken-tutorial.org  

| Spoken Tutorial project is a part of the Talk to a Teacher project.

| More information on this mission is available at  

[http://spoken-tutorial.org/NMEICT-Intro].  

| Thus, we come to the end of this tutorial.

|This is Arya Ratish from IIT Bomaby, signing off.  Thanks for joining us.