Difference between revisions of "Ruby/C3/Object-Oriented-Concept-in-Ruby/English-timed"

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|-
 
|-
 
|  00:01
 
|  00:01
−
| Welcome to this spoken tutorial on ''' Object Oriented Concept''' in '''Ruby'''.  
+
| Welcome to this '''spoken tutorial''' on ''' Object Oriented Concept''' in '''Ruby'''.  
 
    
 
    
 
|-
 
|-
 
| 00:06
 
| 00:06
−
| In this tutorial we will learn to use-  
+
| In this tutorial, we will learn to use-  
  
 
|-
 
|-
 
| 00:08
 
| 00:08
−
| '''classes'''  
+
|* '''classes'''  
  
 
|-
 
|-
 
| 00:09
 
| 00:09
−
|creating '''objects'''  
+
|* creating '''objects'''  
  
 
|-
 
|-
 
| 00:10
 
| 00:10
−
|different ways of defining '''methods''' in '''Ruby'''
+
|* different ways of defining '''methods''' in '''Ruby'''
  
 
|-
 
|-
 
|  00:13
 
|  00:13
−
|Here we are using  
+
|Here we are using:
  
 
|-
 
|-
 
|  00:14
 
|  00:14
−
| ''' Ubuntu''' version 12.04  
+
|* ''' Ubuntu''' version '''12.04'''
  
 
|-
 
|-
 
| 00:16
 
| 00:16
−
|''' Ruby '''1.9.3  
+
|* ''' Ruby 1.9.3'''
  
 
|-
 
|-
 
| 00:19
 
| 00:19
−
|To follow this tutorial, you must have knowledge of ''' Linux''' commands, ''' Terminal''' and '''Text-editor.'''
+
|To follow this tutorial, you must have knowledge of ''' Linux command'''s, ''' Terminal''' and '''Text-editor.'''
 
    
 
    
 
|-
 
|-
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|-
 
|-
 
| 00:44
 
| 00:44
−
| Everything in '''Ruby''' is an object; from a value to a '''string''' or number.  
+
| Everything in Ruby is an object; from a value to a '''string''' or number.  
−
 
+
  
 
|-
 
|-
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| 01:08
 
| 01:08
 
| It is delimited with an ''' “end”.'''  
 
| It is delimited with an ''' “end”.'''  
−
 
  
 
|-
 
|-
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| 01:34
 
| 01:34
 
|The subsequent file names will have underscore separating the words:  
 
|The subsequent file names will have underscore separating the words:  
−
 
  
 
|-
 
|-
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|-
 
|-
 
|  01:45
 
|  01:45
−
| Create a new file in ''' gedit''' as shown in the basic level '''Ruby''' tutorials.  
+
| Create a new file in ''' gedit''' as shown in the basic level '''Ruby tutorials'''.  
  
 
|-
 
|-
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|-
 
|-
 
|  01:57
 
|  01:57
−
|You can pause the tutorial, and type the code as we go through it.  
+
|You can pause the tutorial and type the code as we go through it.  
  
 
|-
 
|-
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|-
 
|-
 
|  02:05
 
|  02:05
−
| Now let us make the ''' class''' useful by adding some '''variables.'''  
+
| Now, let us make the ''' class''' useful by adding some '''variables.'''  
  
 
|-
 
|-
 
| 02:11
 
| 02:11
−
|Then I have defined an ''' instance variable “myinstance”.'''
+
|Then I have defined an '''instance variable “myinstance”.'''
  
 
|-
 
|-
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|-
 
|-
 
|  02:18
 
|  02:18
−
|I have also defined a ''' class variable “myclassvar” '''
+
|I have also defined a ''' class variable “myclassvar” '''.
  
 
|-
 
|-
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|-
 
|-
 
| 02:24
 
| 02:24
−
|Now let us add some code that will make use of this class.  
+
|Now, let us add some code that will make use of this '''class'''.  
  
 
|-
 
|-
 
|  02:30
 
|  02:30
−
| Type ''' puts Order dot instance underscore variables.'''
+
| Type '''puts Order dot instance underscore variables.'''
  
  
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|-
 
|-
 
| 02:43
 
| 02:43
−
| Let us copy and paste that and add it just below the line we added and save it.  
+
| Let us '''copy''' and '''paste''' that and add it just below the line we added and '''save''' it.  
  
 
|-
 
|-
 
| 02:51
 
| 02:51
−
| Now let us execute this code
+
| Now, let us '''execute''' this code.
  
 
|-
 
|-
 
| 02:53
 
| 02:53
−
|Switch to the terminal and type  
+
|Switch to the '''terminal''' and type:
  
 
|-
 
|-
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|-
 
|-
 
| 03:09
 
| 03:09
−
|Now let us type ''' puts Order dot class underscore variables.'''  
+
|Now, let us type: ''' puts Order dot class underscore variables.'''  
  
 
|-
 
|-
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|-
 
|-
 
| 03:21
 
| 03:21
−
| Now let us switch to the '''terminal''' and execute the file like before.   
+
| Now, let us switch to the '''terminal''' and execute the file like before.   
  
 
|-
 
|-
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|-
 
|-
 
|  03:32
 
|  03:32
−
| To now be able to write your own '''class.'''
+
| You should now be able to write your own '''class.'''
  
 
|-
 
|-
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|-
 
|-
 
|  03:43
 
|  03:43
−
| Which means an '''object''' is created from a '''class.'''  
+
| Which means, an '''object''' is created from a '''class.'''  
  
 
|-
 
|-
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|-
 
|-
 
|  03:52
 
|  03:52
−
| How do you declare an '''object'''
+
| How do you declare an '''object'''?
  
 
|-
 
|-
 
|  03:54
 
|  03:54
−
|We declare an '''object''' of a class using the '''new keyword.'''  
+
|We declare an '''object''' of a class using the '''"new" keyword'''.
 
    
 
    
  
 
|-
 
|-
 
| 03:58
 
| 03:58
−
|Here we are declaring an '''object''' of the '''Product class.'''  
+
|Here, we are declaring an '''object''' of the '''Product class.'''  
  
 
|-
 
|-
 
|  04:02
 
|  04:02
−
| Here an '''object''' gets created.  
+
| Here, an '''object''' gets created.  
  
 
|-
 
|-
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|-
 
|-
 
| 04:12
 
| 04:12
−
|This '''object''' is of '''type''': '''Product.'''  
+
|This '''object''' is of type : '''Product.'''  
  
  
 
|-
 
|-
 
| 04:16
 
| 04:16
−
|Now let is look at what an ''' “initialize” method''' is.  
+
|Now, let is look at what an ''' “initialize” method''' is.  
  
 
|-
 
|-
 
| 04:20
 
| 04:20
 
|An ''' initialize method''' is called at the time of '''object''' creation.  
 
|An ''' initialize method''' is called at the time of '''object''' creation.  
−
 
  
 
|-
 
|-
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|-
 
|-
 
| 04:46
 
| 04:46
−
|Create a new file in '''gedit''' as shown in the basic level '''Ruby''' tutorials.  
+
|Create a new file in '''gedit''' as shown in the basic level '''Ruby tutorials'''.  
  
 
|-
 
|-
 
| 04:50
 
| 04:50
−
| And name it '''object undescore initialize dot rb '''
+
| And name it '''object undescore initialize dot rb'''.
  
 
|-
 
|-
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|-
 
|-
 
| 05:00
 
| 05:00
−
| You can pause the tutorial, and type the code as we go through it.   
+
| You can pause the tutorial and type the code as we go through it.   
  
 
|-
 
|-
 
| 05:04
 
| 05:04
−
|Here I have defined a ''' class''' called ''' “Order” '''
+
|Here, I have defined a '''class''' called '''“Order” '''.
  
 
|-
 
|-
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|-
 
|-
 
| 05:13
 
| 05:13
−
| I have defined a '''puts method''' to display the message '''“I have created an object”.
+
| I have defined a ''''puts' method''' to display the message: “I have created an object”.
  
 
|-
 
|-
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|-
 
|-
 
| 05:27
 
| 05:27
−
|Switch to the '''terminal''' and type  
+
|Switch to the '''terminal''' and type:
 
   
 
   
 
|-
 
|-
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|-
 
|-
 
|05:39
 
|05:39
−
|You will see the message ''' “I have created an object” ''' .  
+
|You will see the message ''' “I have created an object”'''.  
  
 
|-
 
|-
 
| 05:43
 
| 05:43
−
|Now let us go back to '''gedit''' and add an '''argument''' to the '''method.'''
+
|Now, let us go back to '''gedit''' and add an '''argument''' to the '''method.'''
  
 
|-
 
|-
 
| 05:48
 
| 05:48
−
|Let us modify the ''' puts''' .   
+
|Let us modify the '''puts'''.   
  
 
|-
 
|-
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|-
 
|-
 
|  05:55
 
|  05:55
−
| Next let us type  
+
| Next, let us type:
  
 
|-
 
|-
 
| 05:56
 
| 05:56
−
|''' Order dot new(“I have created an object”). '''
+
|'''Order dot new(“I have created an object”).'''
  
 
|-
 
|-
 
| 06:04
 
| 06:04
−
|Here we have given an argument to the new method.  
+
|Here, we have given an argument to the new '''method'''.  
  
 
|-
 
|-
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|-
 
|-
 
| 06:13
 
| 06:13
−
|Switch to the ''' terminal''' and type  
+
|Switch to the ''' terminal''' and type:
  
 
|-
 
|-
 
| 06:16
 
| 06:16
−
|''' ruby space object underscore initialize dot rb'''  
+
|'''ruby space object underscore initialize dot rb'''  
  
 
|-
 
|-
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|-
 
|-
 
|  06:33
 
|  06:33
−
|Recall that in '''Ruby, methods''' are the '''functions''' that a '''class''' performs.  
+
|Recall that in Ruby, '''methods''' are the '''functions''' that a '''class''' performs.  
  
 
|-
 
|-
 
| 06:39
 
| 06:39
−
|Each '''method''' in a class is defined within the ''' “def” '''  and ''' “end”''' block.  
+
|Each '''method''' in a class is defined within the '''“def”'''  and '''“end”''' block.  
  
  
 
|-
 
|-
 
| 06:45
 
| 06:45
−
|A multiword ''' method''' name is separated with an '''underscore.'''
+
|A multiword  method-name is separated with an '''underscore.'''
  
 
|-
 
|-
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|-
 
|-
 
| 06:54
 
| 06:54
−
|''' ? (question-mark) '''
+
| '?' (question-mark)  
  
 
|-
 
|-
 
| 06:56
 
| 06:56
−
|''' = (equal to) '''
+
|'=' (equal to). 
  
 
|-
 
|-
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| 07:02
 
| 07:02
 
|Let us look at some examples.  
 
|Let us look at some examples.  
−
 
  
 
|-
 
|-
 
| 07:05
 
| 07:05
−
|Create a new file in ''' gedit''' as shown in the basic level '''Ruby''' tutorials.  
+
|Create a new file in '''gedit''' as shown in the basic level '''Ruby tutorials'''.  
  
 
|-
 
|-
 
| 07:09
 
| 07:09
−
|And name it ''' class underscore methods dot rb'''.
+
|And name it: ''' class underscore methods dot rb'''.
  
 
|-
 
|-
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|-
 
|-
 
| 07:17
 
| 07:17
−
|You can pause the tutorial, and type the code as we go through it.   
+
|You can pause the tutorial and type the code as we go through it.   
  
 
|-
 
|-
 
| 07:21
 
| 07:21
−
|Here I have defined a class named ''' “Animal”.'''
+
|Here, I have defined a class named ''' “Animal”.'''
  
 
|-
 
|-
 
| 07:23
 
| 07:23
−
|Then I have two ''' methods “breathe” ''' and ''' “walk”.'''
+
|Then I have two methods- “breathe” and “walk”.
  
 
|-
 
|-
 
| 07:28
 
| 07:28
−
|They are both defined with the ''' “def” ''' and ''' “end”''' keywords.  
+
|They are both defined with the “def” and “end” keywords.  
  
 
|-
 
|-
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|-
 
|-
 
| 07:36
 
| 07:36
−
|I have assigned it to a variable called  ''' “animal”''' with lowercase ''' “a”.'''
+
|I have assigned it to a variable called  “animal” with lowercase “a”.  
  
 
|-
 
|-
 
| 07:40
 
| 07:40
−
|Then I have invoked the ''' methods “breathe” ''' and ''' “walk” ''' consequtively.  
+
|Then I have invoked the methods “breathe” and “walk” consecutively.  
  
 
|-
 
|-
 
| 07:48
 
| 07:48
−
|Now let us execute the program.  
+
|Now, let us '''execute''' the program.  
  
 
|-
 
|-
 
| 07:51
 
| 07:51
−
|Switch to the '''terminal''' and type  
+
|Switch to the '''terminal''' and type:
  
 
|-
 
|-
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|-
 
|-
 
| 08:02
 
| 08:02
−
|'''“ I breathe” '''
+
|'''“ I breathe” '''
  
 
|-
 
|-
 
| 08:03
 
| 08:03
−
|'''“ I walk” '''
+
|'''“I walk” '''
  
 
|-
 
|-
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|-
 
|-
 
| 08:25
 
| 08:25
−
|And name it '''class underscore methods underscore with underscore trailing underscore characters dot rb'''
+
|And name it '''class underscore methods underscore with underscore trailing underscore characters dot rb'''.
  
 
|-
 
|-
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|-
 
|-
 
| 08:40
 
| 08:40
−
|You can pause the tutorial, and type the code as we go through it.  
+
|You can pause the tutorial and type the code as we go through it.  
  
 
|-
 
|-
 
| 08:45
 
| 08:45
−
|Here I have taken the same class as before as an example.  
+
|Here, I have taken the same '''class''' as before, as an example.  
  
 
|-
 
|-
 
| 08:48
 
| 08:48
−
|Here the '''breathe method''' has a trailing '''“question mark (?)”. '''
+
|Here, the '''"breathe" method''' has a trailing question mark (?).  
  
 
|-
 
|-
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|-
 
|-
 
| 09:00
 
| 09:00
−
|The '''method''' gets invoked by declaring '''animal dot breathe question-mark'''
+
|The '''method''' gets invoked by declaring '''animal dot breathe question-mark'''.
  
 
|-
 
|-
 
| 09:06
 
| 09:06
−
|Switch to the '''terminal''' and type  
+
|Switch to the '''terminal''' and type:
  
 
|-
 
|-
 
| 09:09
 
| 09:09
 
|'''ruby space class underscore methods underscore with underscore trailing underscore characters dot rb'''  and see the output.  
 
|'''ruby space class underscore methods underscore with underscore trailing underscore characters dot rb'''  and see the output.  
−
 
  
 
|-
 
|-
 
| 09:22
 
| 09:22
−
|You will notice the output as : ''' “true” '''
+
|You will notice the output as : ''' “true” '''
−
 
+
  
 
|-
 
|-
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|-
 
|-
 
| 09:41
 
| 09:41
−
|Then let us execute this '''method. '''
+
|Then let us execute this method.  
  
 
|-
 
|-
 
| 09:44
 
| 09:44
−
|Switch to the '''terminal''' and type  
+
|Switch to the '''terminal''' and type:
  
 
|-
 
|-
 
| 09:45
 
| 09:45
−
|'''ruby class underscore methods underscore with underscore trailing underscore characters dot rb '''
+
|'''ruby class underscore methods underscore with underscore trailing underscore characters dot rb'''
−
 
+
  
 
|-
 
|-
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|-
 
|-
 
| 10:13
 
| 10:13
−
|Type '''puts animal dot walk equal to “ hops” '''
+
|Type: '''puts animal dot walk equal to “ hops” '''.
  
 
|-
 
|-
 
| 10:17
 
| 10:17
−
|Now let give it another try.  
+
|Now, let us give it another try.  
  
 
|-
 
|-
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|-
 
|-
 
| 10:42
 
| 10:42
−
|In this tutorial we have learnt-  
+
|In this tutorial, we have learnt-  
  
 
|-
 
|-
 
| 10:44
 
| 10:44
−
|How to declare '''classes '''
+
|* How to declare '''classes '''
  
 
|-
 
|-
 
| 10:46
 
| 10:46
−
|How to create ''' objects''' of a ''' class '''
+
|* How to create '''objects''' of a ''' class'''
  
 
|-
 
|-
 
| 10:48
 
| 10:48
−
|Different ways of defining '''methods''' in '''Ruby'''  
+
|* Different ways of defining '''methods''' in '''Ruby'''.
  
 
|-
 
|-
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|-
 
|-
 
| 10:54
 
| 10:54
−
|Define a '''class Product '''
+
|Define a '''class Product'''
  
 
|-
 
|-
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|-
 
|-
 
|11:05
 
|11:05
−
|Instantiate the object of the class and set and get values using the above 2 methods.  
+
|Instantiate the object of the '''class''' and set and get values using the above 2 methods.  
−
 
+
  
 
|-
 
|-
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|-
 
|-
 
| 11:14
 
| 11:14
−
|It summarises the Spoken Tutorial project.
+
|It summarizes the Spoken Tutorial project.
  
 
|-
 
|-
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|-
 
|-
 
|  11:22
 
|  11:22
−
|  The Spoken Tutorial Project Team :
+
|  The Spoken Tutorial project team:
  
 
|-   
 
|-   
 
| 11:24
 
| 11:24
−
|Conducts workshops using spoken tutorials  
+
|* Conducts workshops using spoken tutorials.
  
 
|-
 
|-
 
|11:27
 
|11:27
−
|Gives certificates to those who pass an online test  
+
|* Gives certificates to those who pass an online test.
  
 
|-
 
|-
 
| 11:30
 
| 11:30
−
|For more details, please write to contact@spoken-tutorial.org
+
|For more details, please write to:
 +
contact@spoken-tutorial.org
  
 
|-
 
|-
 
|  11:36
 
|  11:36
−
| Spoken Tutorial Project is a part of the Talk to a Teacher project.
+
| '''Spoken Tutorial''' project is a part of the '''Talk to a Teacher''' project.
  
 
|-
 
|-
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|-
 
|-
 
| 11:46
 
| 11:46
−
|More information on this Mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro
+
|More information on this mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro.
  
 
|-
 
|-
 
| 11:56
 
| 11:56
−
| This is Anjana Nair signing off. Thank you
+
| This is Anjana Nair, signing off. Thank you.
  
 
|}
 
|}

Revision as of 22:07, 29 October 2015


Time Narration
00:01 Welcome to this spoken tutorial on Object Oriented Concept in Ruby.
00:06 In this tutorial, we will learn to use-
00:08 * classes
00:09 * creating objects
00:10 * different ways of defining methods in Ruby
00:13 Here we are using:
00:14 * Ubuntu version 12.04
00:16 * Ruby 1.9.3
00:19 To follow this tutorial, you must have knowledge of Linux commands, Terminal and Text-editor.
00:24 If not, for relevant tutorials, please visit our website.
00:28 Before we begin, recall that we had created a “ttt” directory earlier.
00:33 Let's go to that directory.
00:35 To ruby hyphen tutorial and classes directory.
00:41 Ruby is an object oriented language.
00:44 Everything in Ruby is an object; from a value to a string or number.
00:49 A class' is a collection of related data and functions.
00:53 It can serve to keep information organized.
00:56 An object is an instantiation of a class.
01:00 A class definition begins with the keyword class.
01:05 It is followed by the name of the class.
01:08 It is delimited with an “end”.
01:11 Let us look at an example of a class.
01:14 class Product
01:16 ruby code
01:17 end
01:20 The name of the class must begin with a capital letter.
01:24 Names that contain more than one word should be camelcased.
01:28 For example,
01:30 UserInformation
01:32 ProductInformation
01:34 The subsequent file names will have underscore separating the words:
01:37 user underscore information
01:40 product underscore information
01:45 Create a new file in gedit as shown in the basic level Ruby tutorials.
01:48 Name it class_definition.rb
01:52 I have a working example of the implementation of classes.
01:57 You can pause the tutorial and type the code as we go through it.
02:02 I have defined a class named Order in this example.
02:05 Now, let us make the class useful by adding some variables.
02:11 Then I have defined an instance variable “myinstance”.
02:15 And I have assigned a value to it.
02:18 I have also defined a class variable “myclassvar” .
02:21 And I have assigned a value to it.
02:24 Now, let us add some code that will make use of this class.
02:30 Type puts Order dot instance underscore variables.


02:36 Before this line, add puts some characters slash n for a new line.
02:43 Let us copy and paste that and add it just below the line we added and save it.
02:51 Now, let us execute this code.
02:53 Switch to the terminal and type:
02:56 ruby space class underscore definition dot rb
03:02 and see the output.
03:05 You will see the instance variable you defined.
03:09 Now, let us type: puts Order dot class underscore variables.
03:15 Let us copy and paste the demarcation, just below the line and save it.
03:21 Now, let us switch to the terminal and execute the file like before.
03:26 You will notice the class variable you defined, also show up.
03:32 You should now be able to write your own class.
03:35 Next, let us look at what an object is.
03:40 An object is an instance of a class.
03:43 Which means, an object is created from a class.
03:46 An object will have the properties and methods defined in the class.
03:52 How do you declare an object?
03:54 We declare an object of a class using the "new" keyword.


03:58 Here, we are declaring an object of the Product class.
04:02 Here, an object gets created.
04:05 product = Product.new
04:09 This process is called initialization of an object.
04:12 This object is of type : Product.


04:16 Now, let is look at what an “initialize” method is.
04:20 An initialize method is called at the time of object creation.
04:26 On calling new on an object, we invoke the initialize method.
04:31 An initialize method may take a list of parameters.
04:37 Like other Ruby methods, it is preceded by the “def” keyword.
04:43 Let us look at an example.
04:46 Create a new file in gedit as shown in the basic level Ruby tutorials.
04:50 And name it object undescore initialize dot rb.
04:55 I have a working example of the object initialization code.
05:00 You can pause the tutorial and type the code as we go through it.
05:04 Here, I have defined a class called “Order” .
05:08 Then I have defined the initialize method, with no argument.
05:13 I have defined a 'puts' method to display the message: “I have created an object”.
05:20 Next, I have defined Order dot new.
05:24 This will invoke the initialize method.
05:27 Switch to the terminal and type:
05:31 ruby space object underscore initialize dot rb
05:36 and see the output.
05:39 You will see the message “I have created an object”.
05:43 Now, let us go back to gedit and add an argument to the method.
05:48 Let us modify the puts.
05:51 It should display the value of the argument passed.
05:55 Next, let us type:
05:56 Order dot new(“I have created an object”).
06:04 Here, we have given an argument to the new method.
06:08 This argument gets passed on to the initialize method.
06:13 Switch to the terminal and type:
06:16 ruby space object underscore initialize dot rb
06:20 and see the output.
06:22 You will see the message “I have created an object” printed out.
06:29 Now, you would have understood what object initialization means.
06:33 Recall that in Ruby, methods are the functions that a class performs.
06:39 Each method in a class is defined within the “def” and “end” block.


06:45 A multiword method-name is separated with an underscore.
06:48 Some of the characters that can be appended to a method name are:
06:54 '?' (question-mark)
06:56 '=' (equal to).
06:58 Each of the characters add some meaning to the method.
07:02 Let us look at some examples.
07:05 Create a new file in gedit as shown in the basic level Ruby tutorials.
07:09 And name it: class underscore methods dot rb.
07:14 I have a working example of class methods code.
07:17 You can pause the tutorial and type the code as we go through it.
07:21 Here, I have defined a class named “Animal”.
07:23 Then I have two methods- “breathe” and “walk”.
07:28 They are both defined with the “def” and “end” keywords.
07:32 I have then initialized the object Animal.
07:36 I have assigned it to a variable called “animal” with lowercase “a”.
07:40 Then I have invoked the methods “breathe” and “walk” consecutively.
07:48 Now, let us execute the program.
07:51 Switch to the terminal and type:
07:53 ruby space class underscore methods dot rb
07:58 and see the output.
08:00 You will notice the lines:
08:02 “ I breathe”
08:03 “I walk”
08:04 printed out.
08:05 This is because you have invoked the two methods “breathe” and “walk”.


08:10 A “puts” statement defined within these methods gives the results you see.
08:16 Next, let us look at how to create methods with a trailing question mark.
08:21 Create a new file in gedit as shown in the basic level Ruby tutorials.
08:25 And name it class underscore methods underscore with underscore trailing underscore characters dot rb.
08:35 I have a working example of class methods with question mark code.
08:40 You can pause the tutorial and type the code as we go through it.
08:45 Here, I have taken the same class as before, as an example.
08:48 Here, the "breathe" method has a trailing question mark (?).
08:52 Such methods are generally used to return boolean values.


08:55 This is based on the method naming convention of Ruby.
09:00 The method gets invoked by declaring animal dot breathe question-mark.
09:06 Switch to the terminal and type:
09:09 ruby space class underscore methods underscore with underscore trailing underscore characters dot rb and see the output.
09:22 You will notice the output as : “true”
09:26 Next, let us define another method called “walk”.
09:30 Let us place an equal-to sign “=(value)” beside it.
09:36 Let us invoke this method by calling animal dot walk.
09:41 Then let us execute this method.
09:44 Switch to the terminal and type:
09:45 ruby class underscore methods underscore with underscore trailing underscore characters dot rb
09:52 and see the output.
09:56 It will give an “undefined method” error.
09:59 This is because the equal to sign has another meaning.
10:03 It is used to assign a value to a method.
10:08 So, let us invoke the method a little differently this time.
10:13 Type: puts animal dot walk equal to “ hops” .
10:17 Now, let us give it another try.
10:20 Switch to the terminal and run the command like before and see the output.
10:27 You will notice that the word “hops” get printed.
10:30 This demonstrates that the equal to sign next to a method means assignment.
10:36 Now you should be able to write your own methods.
10:42 In this tutorial, we have learnt-
10:44 * How to declare classes
10:46 * How to create objects of a class
10:48 * Different ways of defining methods in Ruby.
10:52 As an assignment:
10:54 Define a class Product
10:56 Define methods that you can use to get values of “myvar” and set values for “myvar”.
11:01 To set values, define the method using “=” sign.
11:05 Instantiate the object of the class and set and get values using the above 2 methods.
11:12 Watch the video available at the following link.
11:14 It summarizes the Spoken Tutorial project.
11:18 If you do not have good bandwidth, you can download and watch it.
11:22 The Spoken Tutorial project team:
11:24 * Conducts workshops using spoken tutorials.
11:27 * Gives certificates to those who pass an online test.
11:30 For more details, please write to:

contact@spoken-tutorial.org

11:36 Spoken Tutorial project is a part of the Talk to a Teacher project.
11:39 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
11:46 More information on this mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro.
11:56 This is Anjana Nair, signing off. Thank you.

Contributors and Content Editors

Jyotisolanki, PoojaMoolya, Pratik kamble, Sandhya.np14, Shruti arya

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