Difference between revisions of "Java/C2/Default-constructor/Gujarati"
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|| ''Time''' | || ''Time''' | ||
− | || '''Narration''' | + | || '''Narration''' |
+ | |||
|- | |- | ||
− | | 00: | + | | 00:02 |
− | | ''' | + | | Welcome to the Spoken Tutorial on '''default''' '''constructor''' in''' java'''. |
|- | |- | ||
− | | 00: | + | | 00:07 |
− | | | + | | In this tutorial we will learn |
− | + | |- | |
+ | | 00:10 | ||
+ | | About the default constructor. | ||
− | + | |- | |
− | + | | 00:12 | |
− | + | | And to create a constructor. | |
|- | |- | ||
− | | 00: | + | | 00:15 |
− | | | + | | Here we are using |
− | + | * Ubuntu version 11.10 | |
+ | * Java Development Environment jdk 1.6 and | ||
+ | * Eclipse 3.7.0 | ||
− | |||
− | |||
|- | |- | ||
− | | 00: | + | | 00:26 |
− | | | + | | To follow this tutorial you must know |
|- | |- | ||
− | | 00:29 | + | | 00:29 |
− | | | + | | how to create a class and the object of the class in '''java''' using '''eclipse'''. |
− | |||
− | |||
− | |||
|- | |- | ||
− | | 00: | + | | 00:34 |
− | | | + | | If not, for relevant tutorials please visit our website which is as shown, |
− | + | (http://www.spoken-tutorial.org) | |
− | + | ||
− | + | ||
− | |||
− | |||
− | |||
|- | |- | ||
− | | 00: | + | | 00:42 |
− | | | + | | '''Constructor''' is used to initialize the instance variables. |
− | |||
− | |||
− | |||
|- | |- | ||
− | | | + | | 00:46 |
− | | | + | | It is called at the creation of new object. |
+ | |||
+ | |||
+ | |||
|- | |- | ||
− | | | + | | 00:50 |
− | | | + | | Let us now see how '''constructor''' is defined in java. |
+ | |||
|- | |- | ||
− | | | + | | 00:55 |
− | | | + | | So in the '''eclipse,''' I have already created a java file, '''Student.java''' |
|- | |- | ||
− | | 01: | + | | 01:02 |
− | | | + | | In the Student class we will declare two variables. |
+ | |||
|- | |- | ||
− | | 01: | + | | 01:07 |
− | | | + | | So type '''''int''''' '''''roll_number''''' ''semi-colon'' and '''''String''''' '''''name''''' semi''-colon.'' |
|- | |- | ||
− | | 01: | + | | 01:20 |
− | | | + | | Now let us create a method. |
|- | |- | ||
− | | | + | | 01:22 |
− | | | + | | So type '''''void''''' '''''studentDetail()''''' |
|- | |- | ||
− | | 01: | + | | 01:33 |
− | | | + | | Within curly ''brackets'' type '''''System''''' ''dot'' '''''out''''' ''dot'' '''''println''''' '''''roll_number''''' |
|- | |- | ||
− | | 01: | + | | 01:50 |
− | | | + | | Then '''''System''''' ''dot'' '''''out''''' ''dot'' '''''println''''' '''''name''''' |
|- | |- | ||
− | | | + | |02:03 |
− | | | + | | Now in '''Main''' method we will call this method. |
|- | |- | ||
− | | 02: | + | | 02:08 |
− | | | + | | So let us create an object and call the method. |
+ | |||
|- | |- | ||
− | | 02: | + | | 02:14 |
− | | | + | | So type '''''Student''''' object name '''''stu''''' ''equal'' ''to'' '''''new''''' '''''Student''''' |
|- | |- | ||
− | | 02: | + | | 02:28 |
− | | | + | | Then '''''stu''''' ''dot'' method name i.e'''''studentDetail''''' |
|- | |- | ||
− | | 02: | + | | 02:41 |
− | | | + | |Save and '''Run '''the program. |
|- | |- | ||
− | | 02: | + | | 02:46 |
− | | | + | | We see the output zero and null. |
|- | |- | ||
− | | 02: | + | | 02:49 |
− | | | + | | So, the int variable '''roll_number''' has been initialized to its default value zero. |
|- | |- | ||
− | | 02: | + | | 02:56 |
− | | | + | | And the String '''name''' has been initialized to its default value null. |
− | |||
− | |||
− | |||
|- | |- | ||
− | | | + | | 03:02 |
− | | | + | | If we do not define a constructor then a default constructor is created. |
− | |||
− | |||
− | |||
|- | |- | ||
− | | 03: | + | | 03:08 |
− | | | + | | Default constructor has no parameters. |
|- | |- | ||
− | | 03: | + | | 03:11 |
− | | | + | | It initializes the instance variables to their default value. |
− | |||
− | |||
− | |||
|- | |- | ||
− | | 03: | + | | 03:16 |
− | | | + | | Now let us define a '''constructor.''' |
|- | |- | ||
− | | 03: | + | | 03:18 |
− | | | + | | So type '''''Student''''' ''parenthesis'' and curly brackets. |
− | |||
− | |||
− | |||
|- | |- | ||
− | | | + | | 03:30 |
− | | | + | | Remember the '''Constructor''' has the same name as the class name to which it belongs. |
− | + | ||
− | + | ||
− | + | ||
|- | |- | ||
− | | | + | | 03:38 |
− | | | + | | '''Constructors''' are also similar to methods but there are some important differences. |
|- | |- | ||
− | | | + | | 03:44 |
− | | | + | | '''Save''' and '''Run '''the program. |
|- | |- | ||
− | | | + | | 03:48 |
− | | | + | | We see the same output. |
|- | |- | ||
− | | | + | | 03:51 |
− | | | + | | This is because the '''constructor''', that we defined is same as having no '''constructor.''' |
|- | |- | ||
− | | | + | | 03:58 |
− | | | + | | But here no default '''constructor''' is created because we have defined a '''constructor.''' |
|- | |- | ||
− | | | + | | 04:06 |
− | | | + | | Now lets give values to our variables. |
|- | |- | ||
− | | | + | | 04:11 |
− | | | + | | So inside the '''constructor''' type '''''roll_number''''' ''equal'' ''to'' ''ten'' semicolon. |
|- | |- | ||
− | | | + | | 04:25 |
− | | | + | | And '''''name''''' ''equal'' ''to'' within double ''quotes '''Raman''''' |
|- | |- | ||
− | | | + | | 04:35 |
− | | | + | | Now '''Save''' and '''Run''' the program. |
|- | |- | ||
− | | | + | | 04:43 |
− | | | + | | We see in the output that the '''roll_number''' value is '''ten''' and '''name''' is Raman. |
|- | |- | ||
− | | | + | | 04:50 |
− | | | + | | So the '''constructor''' initializes the instance field. |
|- | |- | ||
− | | | + | | 04:55 |
− | | | + | | Now let us see some difference between '''method''' and a '''constructor'''. |
|- | |- | ||
− | | | + | | 05:01 |
− | | | + | | '''Constructor''' does not have a return type. |
|- | |- | ||
− | | | + | | 05:05 |
− | | | + | |Whereas '''Method''' has a return type. |
|- | |- | ||
− | | | + | | 05:10 |
− | |''' | + | | '''Constructor''' is called using the '''new''' operator. |
|- | |- | ||
− | | | + | | 05:16 |
− | |'' | + | |Whereas the '''Method''' is called using the '''dot''' operator. |
|- | |- | ||
− | | | + | | 05:21 |
− | | | + | | So this were some differences between '''constructor''' and '''method.''' |
|- | |- | ||
− | | | + | | 05:29 |
− | | | + | | So in this tutorial, we have learnt |
|- | |- | ||
− | | | + | | 05:32 |
− | | ''' | + | | About the default constructor. |
+ | |- | ||
+ | | 05:34 | ||
+ | | To define a contructor. | ||
+ | |- | ||
+ | | 05:36 | ||
+ | | And Differences between '''method''' and '''constructor.''' | ||
+ | |||
+ | |||
|- | |- | ||
− | | | + | | 05:41 |
− | | | + | | For self assessment, |
|- | |- | ||
− | | | + | | 05:42 |
− | | | + | | Create a class Employee with variables and a method to display variables. |
|- | |- | ||
− | | | + | | 05:47 |
− | | | + | | And Create a constructor for the class Employee. |
|- | |- | ||
− | | | + | | 05:52 |
− | | | + | | To know more about the Spoken Tutorial Project |
+ | |- | ||
+ | | 05:54 | ||
+ | | 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] | ||
+ | |- | ||
+ | | 06:00 | ||
+ | | It summarizes the Spoken Tutorial project | ||
|- | |- | ||
− | | | + | | 06:03 |
− | | | + | | If you do not have good bandwidth, you can download and watch it |
+ | |||
|- | |- | ||
− | | | + | | 06:06 |
− | | | + | | The Spoken Tutorial Project Team |
|- | |- | ||
− | | | + | | 06:08 |
− | | | + | | Conducts workshops using spoken tutorials |
|- | |- | ||
− | | | + | | 06:11 |
− | | | + | | Gives certificates to those who pass an online test |
|- | |- | ||
− | | | + | | 06:14 |
− | | | + | | For more details, please write to contact@spoken-tutorial.org |
− | + | ||
− | + | ||
|- | |- | ||
− | | | + | | 06:20 |
− | | | + | | Spoken Tutorial Project is a part of the Talk to a Teacher project |
|- | |- | ||
− | | | + | | 06:24 |
− | | | + | | It is supported by the National Mission on Education through ICT, MHRD, Government of India |
|- | |- | ||
− | | | + | | 06:29 |
− | | | + | | 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 http://spoken-tutorial.org/NMEICT-Intro] | ||
Line 301: | Line 300: | ||
|- | |- | ||
− | | | + | | 06:38 |
− | | | + | |This brings us tothe end of the tutorial. |
|- | |- | ||
− | | | + | | 06:40 |
− | | | + | | Thanks for joining. |
|- | |- | ||
− | | | + | | 06:42 |
− | | | + | | This is Prathamesh Salunke signing off. Jai Hind. |
+ | |||
+ | |} |
Revision as of 10:50, 2 September 2013
Time' | Narration |
00:02 | Welcome to the Spoken Tutorial on default constructor in java. |
00:07 | In this tutorial we will learn |
00:10 | About the default constructor. |
00:12 | And to create a constructor. |
00:15 | Here we are using
|
00:26 | To follow this tutorial you must know |
00:29 | how to create a class and the object of the class in java using eclipse.
|
00:34 | If not, for relevant tutorials please visit our website which is as shown,
(http://www.spoken-tutorial.org)
|
00:42 | Constructor is used to initialize the instance variables.
|
00:46 | It is called at the creation of new object.
|
00:50 | Let us now see how constructor is defined in java.
|
00:55 | So in the eclipse, I have already created a java file, Student.java |
01:02 | In the Student class we will declare two variables.
|
01:07 | So type int roll_number semi-colon and String name semi-colon. |
01:20 | Now let us create a method. |
01:22 | So type void studentDetail() |
01:33 | Within curly brackets type System dot out dot println roll_number |
01:50 | Then System dot out dot println name |
02:03 | Now in Main method we will call this method. |
02:08 | So let us create an object and call the method.
|
02:14 | So type Student object name stu equal to new Student |
02:28 | Then stu dot method name i.estudentDetail |
02:41 | Save and Run the program. |
02:46 | We see the output zero and null. |
02:49 | So, the int variable roll_number has been initialized to its default value zero. |
02:56 | And the String name has been initialized to its default value null.
|
03:02 | If we do not define a constructor then a default constructor is created.
|
03:08 | Default constructor has no parameters. |
03:11 | It initializes the instance variables to their default value.
|
03:16 | Now let us define a constructor. |
03:18 | So type Student parenthesis and curly brackets.
|
03:30 | Remember the Constructor has the same name as the class name to which it belongs.
|
03:38 | Constructors are also similar to methods but there are some important differences. |
03:44 | Save and Run the program. |
03:48 | We see the same output. |
03:51 | This is because the constructor, that we defined is same as having no constructor. |
03:58 | But here no default constructor is created because we have defined a constructor. |
04:06 | Now lets give values to our variables. |
04:11 | So inside the constructor type roll_number equal to ten semicolon. |
04:25 | And name equal to within double quotes Raman |
04:35 | Now Save and Run the program. |
04:43 | We see in the output that the roll_number value is ten and name is Raman. |
04:50 | So the constructor initializes the instance field. |
04:55 | Now let us see some difference between method and a constructor. |
05:01 | Constructor does not have a return type. |
05:05 | Whereas Method has a return type. |
05:10 | Constructor is called using the new operator. |
05:16 | Whereas the Method is called using the dot operator. |
05:21 | So this were some differences between constructor and method. |
05:29 | So in this tutorial, we have learnt |
05:32 | About the default constructor. |
05:34 | To define a contructor. |
05:36 | And Differences between method and constructor.
|
05:41 | For self assessment, |
05:42 | Create a class Employee with variables and a method to display variables. |
05:47 | And Create a constructor for the class Employee. |
05:52 | To know more about the Spoken Tutorial Project |
05:54 | Watch the video available at http://spoken-tutorial.org/What_is_a_Spoken_Tutorial |
06:00 | It summarizes the Spoken Tutorial project |
06:03 | If you do not have good bandwidth, you can download and watch it
|
06:06 | The Spoken Tutorial Project Team |
06:08 | Conducts workshops using spoken tutorials |
06:11 | Gives certificates to those who pass an online test |
06:14 | For more details, please write to contact@spoken-tutorial.org |
06:20 | Spoken Tutorial Project is a part of the Talk to a Teacher project |
06:24 | It is supported by the National Mission on Education through ICT, MHRD, Government of India |
06:29 | More information on this Mission is available at
http://spoken-tutorial.org/NMEICT-Intro
|
06:38 | This brings us tothe end of the tutorial. |
06:40 | Thanks for joining. |
06:42 | This is Prathamesh Salunke signing off. Jai Hind. |