Difference between revisions of "Advanced-C++/C2/Classes-And-Objects/English-timed"

|Time

|Narration

 

|  Welcome to the spoken tutorial on '''Classes '''and''' Objects''' in '''C++.'''

| In this tutorial we will learn,

| '''Classes.'''

| '''Objects.'''

 

| '''Encapsulation.''' and

| '''Data abstraction.'''

| To record this tutorial, I am using

|'''Ubuntu OS '''version 11.10

|'''g++ compiler '''version 4.6.1

| Let us start with the introduction to classes.

|'''Class is created using a keyword class'''

| Class links the '''code''' and '''data'''.

| The '''data''' and '''functions''' of the class are called as members of the class.

|  Let us move on to objects.

|'''Behavior''' is defined through member functions called '''methods'''.

| Now let us see the syntax for a class

|Here, '''class''' is a keyword used to define a class.

|'''Public, private and protected''' are the access specifier.

|And here we have defined the Data members and the member functions as public, private and protected.

|This is how we close the class.

|  Now let us see an example

|I have already typed the code on the editor.

| Note that our filename is name '''class hyphen obj dot cpp'''

| In this example we will calculate the area of a square using class.

|  Here we are using the '''std namespace'''

|Here I have not declared any '''access specifier'''.

|So by default it is private.

|Hence variable '''x''' is a '''private''' member of''' class square.'''

| This is the '''public specifier'''

|Function '''area''' is a '''public''' function.

|Now let us move back to our slides to know more about the access specifiers.

| '''Public specifier'''

| A '''public''' member can be used anywhere in the program.

| '''Private specifier'''

|''Private''' members can be used only by the members of the '''class'''.

| '''Protected specifier'''

|'''Protected''' members cannot be accessed from outside the '''class'''.

| Here in this statement we have the''' class''' name

|The''' scope resolution operator''' and the''' '''function name.

| It specifies that function '''area''' is not a global function.

| Here we have passed an argument as '''int a.'''

| Now let us switch back to the slides to know more about the '''scope resolution operator.'''

|To access the variable or function with the same name we use the scope resolution  operator '''::'''.

| Now switch to our program.

|  Here the value of a is stored in x

|  Then we return the area of the square

| Here x is a '''private''' member.

|To access the private parameter we used the public member '''a.'''

| This is how we create an '''object'''

|'''class-name '''followed by the '''object-name'''

|  Here we call the function '''area '''using the''' object sqr '''and a (dot)'''. operator'''.

|Then we pass an argument as 4.

|we set the value of x as 4.  

| | This is our return statement

 

| Now Click on '''Save'''

| Let us execute the program.

| Open the terminal window by pressing '''Ctrl, Alt and T '''keys simultaneously on your keyboard.

| To compile type '''g++ space class hyphen obj dot cpp space hyphen o space class'''

|Press '''Enter'''

|Type'''./class'''(dot slash class)

|Press '''Enter'''

 

| The output is displayed as:  

| Now let us move back to our program.

| The data and '''functions''' combined together in a '''class.'''

|'''Class''' is a single unit.

|In which the data and the function using them is grouped.

|Then we have seen class with the ''' private '''and''' public '''members'''.'''

|Let us move back to our slides.

 

| Let us summarize

|In this tutorial we have learnt,

|Encapsulation

 

|Data Abstraction

| int x;

|'''Public''' functions

 

| int area(int);

|'''Classes'''

 

|class square

|To create object  

|To call a function using '''object''''''sqr dot area();'''  

|  As an assignment  

 

| 06:44

|write a program to find the perimeter of a given circle.

| Watch the video available at the link shown below

|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  

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

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| This is Ashwini Patil from IIT Bombay signing off

 

Thank You for joining.