Difference between revisions of "Ruby/C3/Object-Oriented-Programming-Methods/Gujarati"

| |* '''instance methods'''

| |* '''class methods'''

| |* '''accessor methods'''.

* '''Ubuntu '''version '''12.04'''

| |* '''Ruby 1.9.3'''

| | Let's go to that directory.  ચાલો તે ડિરેક્ટરી પર જઈએ.

| |Create a directory named '''oop-methods''' નામની ડિરેક્ટરી બનાવો અને તેને  cd કરો.

| |  '''Ruby tutorials''' ના વેસિક લેવલ માં બતાવ્યા પ્રમાણે '''gedit ''' માં એક નવી ફાઈલ બનાવો.

| |Switch to the '''terminal''' and type: '''ruby instance_methods.rb ''' and press '''Enter '''to see the output.

| | You will see that it will print the values you initialized the '''object''' with.

| |Namely, "laptop" and "35,000".

| | Next, initialize another '''instance''' or '''object'''.

| |Let us name this object '''product_object_2'''.

| |This time, let us give a different set of values for '''name''' and '''price'''.

| | Now, let us call the '''instance methods- "name" and "price" for this '''object.'''

| | Next, let us switch back to the '''terminal''' and execute the code like before.

| | You will notice that it executes successfully and it prints out the new values.

| |This proves that '''instance methods''' are available to all '''objects''' of the '''class Product'''.

| | You should now be able to write your own '''instance methods.'''

| | Next, let us look at what '''class methods '''are.

| | '''Class methods''' are '''methods '''available only to the '''class.'''

| |These '''methods '''are not available to '''instances''' of the '''class.'''

| |There are different ways you can define '''class methods'''.

| | Let us look at an example.

| | Create a new file in '''gedit '''as shown in the basic level '''Ruby tutorials'''.

| |Name it '''class_methods.rb'''.

| | I have a working example of '''class methods'''.

| |You can pause the tutorial and type the code as we go through it.

| | I have defined a '''Product class''' like before.

| | I have also called an '''initializer''', like before.

| |However, this time I have added an extra '''argument''' called '''description'''.

| |I am also using '''class variables''' to hold the values, unlike '''instance variables''' earlier.

| | This '''class''' will demonstrate to you the 3 different ways one can define '''class methods.'''

| |Checkout the '''class method '''declaration for '''name'''.

| |Here, it is defined using the '''class name "Product"'''.

| | Then, checkout the second '''class methods''' declaration.

| |Here I have used the '''"self" keyword'''.

| | Next, checkout the third way you can define '''class methods'''.

| | Now let us implement these '''class methods'''.

| | Let us first initialize an '''object''' of '''Product,''' like before.

| |This time we are also giving a value for the '''description'''.

| | Now, let us invoke the '''class methods''' as shown here.

| | Now, let us execute the code and inspect the output.

| | Switch to the '''terminal''' and execute the code like before.

| | You will notice that it will print the values for '''name, price '''and''' description.'''

| | Now, you should be able to write your own '''class methods'''.

| | Next we shall see what '''accessor methods''' are.

| | '''Ruby''' uses '''accessor methods''' to access data, defined within '''classes'''.

| |'''Accessor methods''' comprise of '''setter methods''' and '''getter methods'''.

| |'''Setter methods''' set the values.

| |'''Getter methods''' get those values.

| |'''Ruby''' uses the word '''attr_accessor''' to declare these '''methods'''.

| | Let us look at an example of '''accessor methods'''.

| | Create a new file in '''gedit '''as shown in the basic level '''Ruby tutorials'''.

| |Name it '''accessor_methods.rb'''

| | I have a working example of implementing '''accessor methods'''.

| |You can pause the tutorial and type the code as we go through it.

| | I have defined a '''class''' named '''Product,''' in this example.

| |I have declared '''attr_accessor '''for 'name' and 'price'.

| |That is all that is required to use these types of '''methods'''.

| | Now let us put it to action.  

| |I have initialized a '''Product object'''.

| | Then, I have set the '''name''' and '''price''' of the '''product''' object.

 

| |This is possible because the '''attr_declaration,''' by default, creates '''methods''' for setting values.

| | I have then attempted to print the values using the '''getter methods''' for 'name' and 'price'.

| |These '''getter methods''' were also generated by the declaration of '''attr_accessor'''.

 

| | Now let us '''execute''' the code like before.

| | You will notice that it prints the values that were set.

| | By now, you should be able to write your own '''accessor methods'''.

| | One thing to note is that '''accessor methods''' are, by default,''' instance methods.'''

| |Thus they can be accessed by different '''instances''' of the '''class Product'''.

| | In this tutorial, we have learnt about:  '''instance methods''',  '''class methods '''and  '''accessor methods'''.

| | As an assignment: define a '''class''' named '''Temperature'''.

| | Write an '''instance method '''using Ruby's '''accessor method''' syntax.

| | This '''method''' should calculate the '''Celsius '''for the given '''Fahrenheit.'''

| | Watch the video available at the following link.

| |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 at spoken hyphen tutorial dot org.

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

| |It is supported by the National Mission on Education through ICT, MHRD, Government of India.

 

| |More information on this mission is available at:

spoken hyphen tutorial dot org slash NMEICT hyphen Intro.

 

| | This is Anjana Nair, signing off. Thank you.