Difference between revisions of "Java/C2/Parameterized-constructors/English-timed"

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| Welcome to the Spoken Tutorial on '''parameterized''' '''constructor''' in''' java'''.
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| Welcome to the Spoken Tutorial on '''parametrized''' '''constructor''' in''' java'''.
  
 
|-
 
|-
 
|  00:08
 
|  00:08
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|  In this tutorial we will learn  
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|  In this tutorial we will learn:
  
 
|-
 
|-
 
|  00:10
 
|  00:10
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|About a '''parametrized''' '''constructor'''
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|* About a '''parametrized''' '''constructor'''.
  
 
|-
 
|-
 
|  00:13
 
|  00:13
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| And to create a '''parameterized''' '''constructor'''
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|* And to create a '''parametrized''' '''constructor'''.
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+
−
 
+
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+
  
 
|-
 
|-
 
| 00:17
 
| 00:17
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|  Here we are using  
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|  Here we are using:
−
 
+
 
* Ubuntu version 11.10 OS
 
* Ubuntu version 11.10 OS
 
* Java Development kit  1.6
 
* Java Development kit  1.6
 
*And  Eclipse 3.7.0
 
*And  Eclipse 3.7.0
−
 
−
 
  
 
|-
 
|-
 
|  00:29
 
|  00:29
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|  To follow this tutorial you must know  
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|  To follow this tutorial, you must know  
  
 
|-
 
|-
 
|  00:32
 
|  00:32
 
|how to create a default '''constructor''' in '''java''' using '''eclipse'''.
 
|how to create a default '''constructor''' in '''java''' using '''eclipse'''.
−
 
  
 
|-
 
|-
 
|  00:37
 
|  00:37
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|If not, for relevant tutorials please visit our website which is as shown,
+
|If not, for relevant tutorials, please visit our website which is as shown.
−
 
+
http://www.spoken-tutorial.org  
−
('''http'''://'''www.spoken'''-'''tutorial.org''')
+
−
 
+
  
 
|-
 
|-
 
|  00:44
 
|  00:44
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|What is a '''parameterized''' '''constructor'''?
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|What is a '''parametrized''' '''constructor'''?
 
|-
 
|-
 
|  00:48
 
|  00:48
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|A '''constructor''' that have parameter is called a '''parameterized''' '''constructor'''.
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|A '''constructor''' that has parameter is called a '''parametrized''' '''constructor'''.
−
 
+
  
 
|-
 
|-
 
|  00:55
 
|  00:55
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|It can have one or more than one parameter.
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|It can have one or more than one parameters.
  
 
|-
 
|-
 
| 00:59
 
| 00:59
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|  Let us now create a '''parameterized constructor.'''
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|  Let us now create a '''parametrized constructor.'''
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+
  
 
|-
 
|-
 
|  01:03
 
|  01:03
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|So in the eclipse, I have  ''' Student.java '''file.
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|So in the '''eclipse''', I have  ''' Student.java '''file.
  
 
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|  01:15
 
|  01:15
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| Now Inside the '''constructor''' we will give the variables their default value.
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| Now, inside the '''constructor''' we will give the variables their default value.
−
 
+
  
 
|-
 
|-
 
|  01:21
 
|  01:21
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|So '''''roll_number '''is''' '''equal''' '''to''' zero''''' instead of '''''ten'''''.
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|So '''roll_number '''is equal to zero instead of ten.
  
 
|-
 
|-
 
|  01:27
 
|  01:27
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|And '''''name''' is equal to '''null''''' instead of '''''Raman'''''.  
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|And '''name''' is equal to '''null''' instead of '''Raman'''.  
  
 
|-
 
|-
 
|  01:33
 
|  01:33
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|  Then type '''''System '''dot''' out '''dot''' println I am a  default constructor.'''''
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|  Then type '''System '''dot''' out '''dot''' println I am a  default constructor.'''
−
 
+
  
 
|-
 
|-
 
|  01:55  
 
|  01:55  
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|So we have created a '''constructor''' with no parameters.  
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|So, we have created a '''constructor''' with no parameters.  
  
 
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|-
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|  02:11
 
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|So type '''''Student''' parentheses.''
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|So, type: '''Student''' parentheses.
  
 
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|  02:17
 
|  02:17
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|Inside ''parenthesis'' '''''int the_roll_number '''''comma''''' String the_name.'''''
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|Inside parenthesis '''int the_roll_number '''comma''' String the_name'''.
  
 
|-
 
|-
 
|  02:36
 
|  02:36
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|  So what we have done, is declared a '''constructor''' with parameters.
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|  So, what we have done is declared a '''constructor''' with parameters.
  
 
|-
 
|-
 
|  02:43
 
|  02:43
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|The name of the '''constructor''' '''Student''' that is the class name.
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|The name of the '''constructor''' '''Student''' that is the '''class''' name.
  
 
|-
 
|-
 
| 02:49
 
| 02:49
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|  Inside the paranthesis we have given two parameters to the '''constructor'''.
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|  Inside the parentheses, we have given two parameters to the '''constructor'''.
  
 
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| Now inside curly brackets type
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| Now, inside curly brackets type:
  
 
|-
 
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|  03:05
 
|  03:05
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|'''''System '''dot''' out '''dot''' println I am a parameterized constructor '''''
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|'''System '''dot''' out '''dot''' println I am a parametrized constructor'''.
  
 
|-
 
|-
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|  03:43
 
|  03:43
 
|And'' '''name''' is equal to '''the_name'''.''
 
|And'' '''name''' is equal to '''the_name'''.''
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|-
 
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|  So type,'''stu2.studentDetail'''.
 
|  So type,'''stu2.studentDetail'''.
 
   
 
   
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|  04:38  
 
|  04:38  
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|  06:00
 
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|  Let us see the common errors, when we call a '''parameterised''' '''constructor.'''
 
|  Let us see the common errors, when we call a '''parameterised''' '''constructor.'''
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|-
 
|-
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|  09:56
 
|  09:56
 
|This is how we create'''Parameterised constructor''' in '''java'''.
 
|This is how we create'''Parameterised constructor''' in '''java'''.
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|-
 
|-
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|  10:07
 
|  10:07
 
|  The variables in a class must be initialized each time an instance is created.
 
|  The variables in a class must be initialized each time an instance is created.
−
 
  
 
|-
 
|-
 
|  10:13
 
|  10:13
 
|It can be tedious to initialize all the variables.  
 
|It can be tedious to initialize all the variables.  
−
 
  
 
|-
 
|-
 
|  10:18
 
|  10:18
 
|So java allows objects to initialize themselves when they are created.
 
|So java allows objects to initialize themselves when they are created.
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|-
 
|-
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|-
 
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|  10:30
 
|  10:30
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| So in this tutorial, we have learnt  
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| So in this tutorial, we have learnt:
  
 
|-
 
|-
 
|  10:33
 
|  10:33
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|To create '''parameterized''' '''constructor.'''
+
|* To create '''parametrized''' '''constructor.'''
  
 
|-
 
|-
 
|  10:36  
 
|  10:36  
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|Functionality of '''parameterized''' '''constructor.'''
+
|* Functionality of '''parametrized''' '''constructor.'''
  
 
|-
 
|-
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|-
 
|-
 
|10:53
 
|10:53
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|To know more about the Spoken Tutorial Project
+
|To know more about the Spoken Tutorial Project,
 
|-
 
|-
 
|  10:56
 
|  10:56
−
| Watch the video available at [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial http://spoken-][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial tutorial.org/What_is_a_Spoken_Tutorial]  
+
| watch the video available at [http://spoken-tutorial.org/What_is_a_Spoken_Tutorial]
 +
 
 
|-
 
|-
 
|  11:02
 
|  11:02
−
| It summarizes the Spoken Tutorial project  
+
| It summarizes the Spoken Tutorial project.
  
 
|-
 
|-
 
|  11:06
 
|  11:06
−
|If you do not have good bandwidth, you can download and watch it  
+
|If you do not have good bandwidth, you can download and watch it.
−
 
+
−
 
+
  
 
|-
 
|-
 
|  11:10
 
|  11:10
−
|  The Spoken Tutorial Project Team
+
|  The Spoken Tutorial project team:
  
 
|-
 
|-
 
|  11:12
 
|  11:12
−
| Conducts workshops using spoken tutorials  
+
| Conducts workshops using spoken tutorials.
  
 
|-
 
|-
 
|  11:14
 
|  11:14
−
| Gives certificates for those who pass an online test  
+
| Gives certificates for those who pass an online test.
  
 
|-
 
|-
 
|  11:18
 
|  11:18
 
|For more details, please write to contact@spoken-tutorial.org  
 
|For more details, please write to contact@spoken-tutorial.org  
−
 
−
 
  
 
|-
 
|-
 
|  11:24
 
|  11:24
−
| 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.
  
 
|-
 
|-
 
|  11:28
 
|  11:28
−
| It is supported by the National Mission on Education through ICT, MHRD, Government of India  
+
| It is supported by the National mission on Education through ICT, MHRD, Government of India.
  
 
|-
 
|-
 
|  11:34
 
|  11:34
−
| More information on this Mission is available at  
+
| More information on this Mission is available at:
−
 
+
[http://spoken-tutorial.org/NMEICT-Intro]  
−
* [http://spoken-tutorial.org/NMEICT-Intro http://spoken-tutorial.org/NMEICT-Intro]  
+
−
 
+
−
 
+
  
 
|-
 
|-
 
| 11:43
 
| 11:43
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|  This brings us to   the end of the tutorial.
+
|  This brings us to the end of the tutorial.
  
 
|-
 
|-
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|-
 
|-
 
|  11:47
 
|  11:47
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|This is Prathamesh Salunke signing off.  
+
|This is Prathamesh Salunke, signing off.  
  
 
Jai Hind.  
 
Jai Hind.  
  
 
|}
 
|}

Revision as of 21:42, 31 March 2015

Time Narration
00:02 Welcome to the Spoken Tutorial on parametrized constructor in java.
00:08 In this tutorial we will learn:
00:10 * About a parametrized constructor.
00:13 * And to create a parametrized constructor.
00:17 Here we are using:
  • Ubuntu version 11.10 OS
  • Java Development kit 1.6
  • And Eclipse 3.7.0
00:29 To follow this tutorial, you must know
00:32 how to create a default constructor in java using eclipse.
00:37 If not, for relevant tutorials, please visit our website which is as shown.

http://www.spoken-tutorial.org

00:44 What is a parametrized constructor?
00:48 A constructor that has parameter is called a parametrized constructor.
00:55 It can have one or more than one parameters.
00:59 Let us now create a parametrized constructor.
01:03 So in the eclipse, I have Student.java file.
01:09 We created this file in the previous tutorial.
01:15 Now, inside the constructor we will give the variables their default value.
01:21 So roll_number is equal to zero instead of ten.
01:27 And name is equal to null instead of Raman.
01:33 Then type System dot out dot println I am a default constructor.
01:55 So, we have created a constructor with no parameters.
02:00 In java, such constructor is also called a default constructor.
02:07 Now we will create another constructor.
02:11 So, type: Student parentheses.
02:17 Inside parenthesis int the_roll_number comma String the_name.
02:36 So, what we have done is declared a constructor with parameters.
02:43 The name of the constructor Student that is the class name.
02:49 Inside the parentheses, we have given two parameters to the constructor.
02:57 We can give any number of parameters to the constructor.
03:02 Now, inside curly brackets type:
03:05 System dot out dot println I am a parametrized constructor.
03:29 Then roll_number is equal to the_roll_number.
03:43 And name is equal to the_name.
03:53 So we have created a constructor with parameters.
03:58 Now let's call this constructor.
04:02 So in the main method type; student stu2 equal to' new student within parentheses 11 comma in double quotes Raju
04:28 Let's call the studentDetail method.
04:31 So type,stu2.studentDetail.
04:38 Save and Run the program
04:44 We see the output on the console.
04:48 The default constructor is called first.
04:52 It initializes the variables to their default value.
04:56 Then the parameterized constructor is called.
05:00 It initializes the variables to the values that are passed as the argument.
05:05 That is 11 and Raju.
05:08 Let us see how the parametrized constructor works.
05:12 When we call the parameterized constructor, we pass two values to it.
05:18 These are called arguments.
05:22 The value 11 is copied to the parameter the_roll_number.
05:31 And the valueRaju is copied to the parameter the_name.
05:41 Then the value of the_roll_number is assigned to roll_number.
05:50 And the value of the_name is assigned to name.
05:55 Hence in the output we see 11 and Raju.
06:00 Let us see the common errors, when we call a parameterised constructor.
06:07 Suppose we pass a single argument to the constructor.
06:11 So remove Raju.
06:15 We get an error. It states that “The constructor Student with parameter (int) is undefined.”
06:24 So the number of arguments must match the number of parameters.
06:30 Here we can retype Raju and resolve the error.
06:36 Alternatively, what we can do is define another constructor with a single parameter.
06:42 Let us do that
06:45 So Student within paranthesis int r number.
07:01 Inside curly brackets, type System dot out dot println
07:13 I am a constructor with a single parameter.
07:29 Then roll_number is equal to r number
07:48 Save the file.
07:51 We see that the error is resolved when we define the constructor.
07:58 Let's Run the program.
08:02 On the console we see that the roll number is assigned the value 11.
08:08 While name is null since the constructor takes only one argument.
08:18 Let us now call back our constructor with two parameters.
08:23 So type Student stu3 is equal to new Student.
08:40 11 comma Raju.
08:46 ThenStu3 dot studentDetail
08:58 Suppose here we pass 11 as String, so add double quotes.
09:08 We get an error.
09:10 It states that “The constructor Student String commaString is undefined.”
09:17 So even the datatype of the argument must match with that of the parameter.
09:25 So now remove the quotes and Save the file.
09:32 Now we do not see an error.
09:35 So Run the program.
09:38 In the output we see three constructors.
09:42 The first one is the default constructor.
09:45 The second one is theConstructor with one parameter.
09:50 And this third one is theConstructor with two parameters.
09:56 This is how we createParameterised constructor in java.
10:05 Why constructor?
10:07 The variables in a class must be initialized each time an instance is created.
10:13 It can be tedious to initialize all the variables.
10:18 So java allows objects to initialize themselves when they are created.
10:25 This is performed through the use of a constructor.
10:30 So in this tutorial, we have learnt:
10:33 * To create parametrized constructor.
10:36 * Functionality of parametrized constructor.
10:39 And the advantage of using constructor.
10:44 For self assessment, create a class Employee.
10:48 Create constructors with different number of parameters.
10:53 To know more about the Spoken Tutorial Project,
10:56 watch the video available at [1]
11:02 It summarizes the Spoken Tutorial project.
11:06 If you do not have good bandwidth, you can download and watch it.
11:10 The Spoken Tutorial project team:
11:12 Conducts workshops using spoken tutorials.
11:14 Gives certificates for those who pass an online test.
11:18 For more details, please write to contact@spoken-tutorial.org
11:24 Spoken Tutorial Project is a part of the Talk to a Teacher project.
11:28 It is supported by the National mission on Education through ICT, MHRD, Government of India.
11:34 More information on this Mission is available at:

[2]

11:43 This brings us to the end of the tutorial.
11:46 Thanks for joining.
11:47 This is Prathamesh Salunke, signing off.

Jai Hind.

Contributors and Content Editors

Gaurav, PoojaMoolya, Ranjana, Sandhya.np14, Sneha

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