Difference between revisions of "Java/C2/Non-static-block/English-timed"

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|-
 
|-
 
|  00:02
 
|  00:02
|  Welcome to the Spoken Tutorial on '''Non-static block '''in '''java'''.
+
|  Welcome to the Spoken Tutorial on '''Non-static block''' in '''java'''.
  
 
|-
 
|-
 
|  00:06
 
|  00:06
|  In this tutorial we will learn  
+
|  In this tutorial, we will learn:
 
+
  
 
|-
 
|-
 
|  00:08
 
|  00:08
| About '''non-static''' '''block'''
+
|About '''non-static''' '''block'''
  
 
|-
 
|-
 
|  00:10
 
|  00:10
| When  a '''non-static block '''executed?
+
|When  a '''non-static block''' is executed?
  
 
|-
 
|-
 
|  00:13
 
|  00:13
| Simple example of '''non-static block'''
+
|Simple example of '''non-static block'''
  
 
|-
 
|-
 
|  00:16
 
|  00:16
 
|And Why we need '''constructors'''?
 
|And Why we need '''constructors'''?
 
 
  
 
|-
 
|-
 
| 00:18
 
| 00:18
|  Here we are using  
+
|  Here we are using:
 
+
'''Ubuntu version 11.10'''
* Ubuntu version 11.10  
+
'''Java Development Environment jdk 1.6'''
* Java Development Environment jdk 1.6
+
And  '''Eclipse IDE 3.7.0'''
*And  Eclipse IDE 3.7.0
+
 
+
 
+
  
 
|-
 
|-
 
| 00:26
 
| 00:26
|To follow this tutorial you must know  
+
|To follow this tutorial, you must know  
  
 
|-
 
|-
 
|  00:29
 
|  00:29
|How to   create a '''constructor''' in '''Java''' using '''Eclipse'''
+
|how to create a '''constructor''' in '''Java''' using '''Eclipse'''.
  
 
|-
 
|-
 
|  00:33
 
|  00:33
| 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''')
+
  
 
|-
 
|-
 
|  00:38
 
|  00:38
| Now we will see what a '''non-static block''' is.
+
| Now we will see, what a '''non-static block''' is.
 
+
  
 
|-
 
|-
 
|  00:42
 
|  00:42
 
| Any code written between two curly brackets is a '''non-static block'''.
 
| Any code written between two curly brackets is a '''non-static block'''.
 
  
 
|-
 
|-
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|-
 
|-
 
|  00:54
 
|  00:54
|A  '''non-static block''' is executedfor each object that is created.  
+
|A  '''non-static block''' is executed for each object that is created.  
  
 
|-
 
|-
 
|  00:58
 
|  00:58
 
| It executes before the '''constructor''''s execution.
 
| It executes before the '''constructor''''s execution.
 
  
 
|-
 
|-
 
|  01:04
 
|  01:04
 
| It can initialize''' instance member variables '''of the class.
 
| It can initialize''' instance member variables '''of the class.
 
  
 
|-
 
|-
 
|  01:08
 
|  01:08
 
| Any other execution like calculation could also be given in the block.
 
| Any other execution like calculation could also be given in the block.
 
  
 
|-
 
|-
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|-
 
|-
 
|  01:22
 
|  01:22
|  I have already opened a class named '''NonStaticTest''' in '''Eclipse.'''
+
|  I have already opened a '''class''' named '''NonStaticTest''' in '''Eclipse.'''
 
+
  
 
|-
 
|-
 
|  01:28
 
|  01:28
| I also have a created a '''class '''named '''A''' .
+
| I also have a created a '''class''' named '''A''' .
 
+
  
 
|-
 
|-
 
|  01:33
 
|  01:33
| Now inside '''class''' '''A ''', I will first create a variable of type '''int'''.
+
| Now inside '''class''' '''A''', I will first create a variable of type '''int'''.
 
+
  
 
|-
 
|-
 
|  01:38
 
|  01:38
| So type '''int''' a semicolon, then press ''Enter''
+
| So, type: '''int a''' semicolon, then press '''Enter'''.
 
+
  
 
|-
 
|-
 
|  01:46
 
|  01:46
| Within curly brackets type '''System''' ''dot '''''out''' ''dot'' '''println''' within brackets and double quotes '''Non static''' '''block of an instance of Class A '''''semicolon''.
+
| Within curly brackets, type: '''System''' dot '''out''' dot '''println''' within brackets and double quotes '''Non static block of an instance of Class A''' semicolon.
 
+
  
 
|-
 
|-
 
|  02:12
 
|  02:12
| Then type '''System '''''dot'' '''out''' ''dot '''''println''' within brackets and double quotes '''The value of a''' is ''plus '''''a '''''semicolon''.
+
| Then, type: '''System''' dot '''out''' dot '''println''' within brackets and double quotes '''The value of a is''' plus '''a''' semicolon.
 
+
  
 
|-
 
|-
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|-
 
|-
 
|  02:35
 
|  02:35
| So type '''public A''' ''opening and closing brackets'', open the ''curly brackets''  press '''Enter'''.
+
| So, type: '''public A''' opening and closing brackets open the curly brackets press '''Enter'''.
 
+
  
 
|-
 
|-
 
|  02:51
 
|  02:51
| Then type  '''System''' ''dot '''''out '''''dot'' '''println''' within brackets and double quotes '''Constructing object of type A''' semicolon.
+
| Then type: '''System''' dot '''out''' dot '''println''' within brackets and double quotes '''Constructing object of type A''' semicolon.
 
+
  
 
|-
 
|-
 
|  03:10
 
|  03:10
| Then type '''System''' ''dot'' '''out '''''dot '''''println''' within brackets and double quotes '''The value of a '''is ''plus'' '''a '''''semicolon''.
+
| Then type: '''System''' dot '''out '''dot '''println''' within brackets and double quotes '''The value of a is''' plus '''a ''' semicolon.
 
+
  
 
|-
 
|-
 
|  03:35
 
|  03:35
 
| Now save this file.
 
| Now save this file.
 +
 
|-
 
|-
 
|  03:44
 
|  03:44
| Inside  '''class NonStaticTest''' in''' Eclipse '''let us create an '''object '''of the '''class A'''.
+
| Inside  '''class NonStaticTest''' in '''Eclipse''' let us create an '''object''' of the '''class A'''.
 
+
  
 
|-
 
|-
 
|  03:53
 
|  03:53
| So type '''A''' ''space '''''a1''' ''equal to''''' new''' ''space'' '''A''' opening and closing brackets semicolon
+
| So, type: '''A''' space '''a1''' equal to ''' new''' space '''A''' opening and closing brackets semicolon.
 
+
  
 
|-
 
|-
 
|  04:08
 
|  04:08
| Next line we will create one more object of class '''A'''.  
+
| Next line, we will create one more object of class '''A'''.  
  
 
|-
 
|-
 
|  04:12
 
|  04:12
|So type '''A''''' space'' '''a2''' ''equal to'' '''new '''''space'' '''A''' opening and closing brackets semicolon.
+
|So, type: '''A''' space '''a2''' equal to '''new ''' space '''A''' opening and closing brackets semicolon.
 
+
  
 
|-
 
|-
 
|  04:25
 
|  04:25
|Now  Save and run the file. So press '''Ctrl &S''' and '''Ctrl &F11 '''keys
+
|Now, '''Save''' and '''run''' the file. So, press '''Ctrl & S''' and '''Ctrl & F11''' keys.
 
+
  
 
|-
 
|-
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| 04:35
 
| 04:35
 
| As we can see when the first''' object '''is created, the '''non-static block''' is executed.
 
| As we can see when the first''' object '''is created, the '''non-static block''' is executed.
 
  
 
|-
 
|-
 
|  04:45
 
|  04:45
|  '''non-static block'''  of an''' instance  of class A '''  and the''' instance variable A '''is initialized to '''0'''.
+
|  '''Non-static block'''  of an '''instance  of class A'''  and the''' instance variable 'a' '''is initialized to '''0'''.
 
+
  
 
|-
 
|-
 
|  04:53
 
|  04:53
| Only after that the '''constructor''' is executed. Constructing object of type A  
+
| Only after that the '''constructor''' is executed. Constructing object of type '''A'''.
 
+
  
 
|-
 
|-
 
|  05:02
 
|  05:02
| And here the''' instance variable''' is again initialized to '''0'''.
+
| And here, the''' instance variable''' is again initialized to '''0'''.
 
+
  
 
|-
 
|-
 
|  05:07
 
|  05:07
 
| Then again when the second '''object''' is created, the '''non-static block''' is executed.
 
| Then again when the second '''object''' is created, the '''non-static block''' is executed.
 
  
 
|-
 
|-
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|  05:20
 
|  05:20
 
|  We can have multiple '''non-static blocks''' in a '''class'''.
 
|  We can have multiple '''non-static blocks''' in a '''class'''.
 
  
 
|-
 
|-
 
|  05:25
 
|  05:25
 
| In this case they execute in the sequence in which they appear in the '''class.'''
 
| In this case they execute in the sequence in which they appear in the '''class.'''
 
  
 
|-
 
|-
 
|  05:30
 
|  05:30
 
| We can try that now.
 
| We can try that now.
 
  
 
|-
 
|-
 
|  05:34
 
|  05:34
| Include one more block after the first one in class A.
+
| Include one more block after the first one in class '''A'''.
  
 
|-
 
|-
 
|  05:43
 
|  05:43
| So again type inside curly brackets.
+
| So, again type inside curly brackets:
 
+
  
 
|-
 
|-
 
|  05:47
 
|  05:47
|   '''System''' ''dot '''''out''' ''dot'' '''println''' within brackets and double quotes '''Second''' '''Non static''' '''block of an instance of Class A '''''semicolon''.
+
| '''System''' dot '''out''' dot '''println''' within brackets and double quotes '''Second Non static block of an instance of Class A''' semicolon.
 
+
  
 
|-
 
|-
 
|  06:08
 
|  06:08
| Then type '''System '''''dot'' '''out''' ''dot '''''println''' within brackets and double quotes '''The value of a''' is ''plus '''''a '''''semicolon''.
+
| Then type: '''System ''' dot '''out''' dot '''println''' within brackets and double quotes '''The value of a is''' plus '''a ''' semicolon .
 
+
  
 
|-
 
|-
 
|  06:30
 
|  06:30
| Now save this file ,press''' Ctrl & S key ''' simultaneously then press ''' Ctrl & F11 '''  to   run the program.
+
| Now, save this file , press''' Ctrl & S''' key  simultaneously then press ''' Ctrl & F11 '''  to '''run''' the program.
  
 
|-
 
|-
Line 247: Line 212:
 
|-
 
|-
 
|  06:48
 
|  06:48
|   we  see that after the first block is executed, the second is executed.
+
| We see that after the first block is executed, the second is executed.
 
+
  
 
|-
 
|-
Line 257: Line 221:
 
|  07:07
 
|  07:07
 
| Now  you might feel why do we need '''constructors.'''
 
| Now  you might feel why do we need '''constructors.'''
 
  
 
|-
 
|-
 
|  07:10
 
|  07:10
 
| The answer is we don't need the '''default constructor'''.
 
| The answer is we don't need the '''default constructor'''.
 
  
 
|-  
 
|-  
 
|  07:15
 
|  07:15
 
| But the '''non-static block''' cannot be '''parameterized'''.
 
| But the '''non-static block''' cannot be '''parameterized'''.
 
  
 
|-
 
|-
 
|  07:18
 
|  07:18
| You cannot have''' objects''' taking values from out side.
+
| You cannot have '''objects''' taking values from out side.
 
+
  
 
|-
 
|-
 
|  07:22
 
|  07:22
| So '''non-static block '''is not a substitute for '''constructor.'''  
+
| So '''non-static block''' is not a substitute for '''constructor.'''  
  
 
|-
 
|-
 
|  07:27
 
|  07:27
| So let us summarizes
+
| So, let us summarize.
  
 
|-
 
|-
 
|  07:29
 
|  07:29
|  In this tutorial we learnt :
+
|  In this tutorial we have learnt  
 
+
  
 
|-
 
|-
 
|  07:32
 
|  07:32
| About '''non-static block'''   and how to use this block.
+
| about '''non-static block''' and how to use this block.
 
+
 
+
 
+
  
 
|-
 
|-
 
| 07:35
 
| 07:35
|  For self assessment,
+
|  For self assessment: Create a '''class '''named '''B.'''
  
|-
 
| 07:36
 
|  create a '''class '''named '''B.'''
 
 
|-
 
|-
 
| 07:39
 
| 07:39
|   Create a '''non-static block''' and a '''constructor''' as shown in the tutorial.
+
|Create a '''non-static block''' and a '''constructor''' as shown in the tutorial.
  
 
|-
 
|-
 
| 07:44
 
| 07:44
| Create an '''object''' of '''class B''' in the '''class NonStaticTest '''already created'''.'''
+
|Create an '''object''' of '''class B''' in the '''class NonStaticTest '''already created.
  
 
|-
 
|-
 
| 07:49
 
| 07:49
|   Check the output.
+
|Check the output.
 
+
 
+
  
 
|-
 
|-
 
|  07:51
 
|  07:51
|  To know more about the Spoken Tutorial Project
+
|  To know more about the Spoken Tutorial Project,
 
|-
 
|-
 
| 07:53
 
| 07:53
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.
 
|-
 
|-
 
| 07:56
 
| 07:56
|  It summarizes the Spoken Tutorial project  
+
|  It summarizes the Spoken Tutorial project.
  
 
|-
 
|-
 
| 08:00
 
| 08:00
|  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.
 
+
 
+
  
 
|-
 
|-
 
|  08:03
 
|  08:03
| The Spoken Tutorial Project Team
+
| The Spoken Tutorial project team:
  
 
|-
 
|-
 
| 08:06
 
| 08:06
|  Conducts workshops using spoken tutorials  
+
|  Conducts workshops using spoken tutorials.
  
 
|-
 
|-
 
| 08:08
 
| 08:08
|  Gives certificates for those who pass an online test  
+
|  Gives certificates to those who pass an online test.
  
 
|-
 
|-
 
| 08:12
 
| 08:12
 
|  For more details, please write to contact@spoken-tutorial.org  
 
|  For more details, please write to contact@spoken-tutorial.org  
 
 
  
 
|-
 
|-
 
|  08:18
 
|  08:18
 
   
 
   
|  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.
  
 
|-
 
|-
 
| 08:22
 
| 08:22
|   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.
  
 
|-
 
|-
 
| 08:28
 
| 08:28
|  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]
+
 
+
 
+
  
 
|-
 
|-
Line 372: Line 315:
 
|-
 
|-
 
| 08:40
 
| 08:40
|  This is Arya Ratish from IIT BOmbay signing off. Thanks for joining.
+
|  This is Arya Ratish from IIT Bombay, signing off. Thanks for joining.
 
+
 
   
 
   
 
|}
 
|}

Latest revision as of 15:30, 28 March 2017

Time Narration
00:02 Welcome to the Spoken Tutorial on Non-static block in java.
00:06 In this tutorial, we will learn:
00:08 About non-static block
00:10 When a non-static block is executed?
00:13 Simple example of non-static block
00:16 And Why we need constructors?
00:18 Here we are using:

Ubuntu version 11.10 Java Development Environment jdk 1.6 And Eclipse IDE 3.7.0

00:26 To follow this tutorial, you must know
00:29 how to create a constructor in Java using Eclipse.
00:33 If not, for relevant tutorials, please visit our website which is as shown.

http://www.spoken-tutorial.org

00:38 Now we will see, what a non-static block is.
00:42 Any code written between two curly brackets is a non-static block.
00:46 We can see the syntax here.
00:51 When is a non-static block executed ?
00:54 A non-static block is executed for each object that is created.
00:58 It executes before the constructor's execution.
01:04 It can initialize instance member variables of the class.
01:08 Any other execution like calculation could also be given in the block.
01:14 Now, let us switch to Eclipse and try to use a non-static block.
01:22 I have already opened a class named NonStaticTest in Eclipse.
01:28 I also have a created a class named A .
01:33 Now inside class A, I will first create a variable of type int.
01:38 So, type: int a semicolon, then press Enter.
01:46 Within curly brackets, type: System dot out dot println within brackets and double quotes Non static block of an instance of Class A semicolon.
02:12 Then, type: System dot out dot println within brackets and double quotes The value of a is plus a semicolon.
02:32 Now we will declare a constructor.
02:35 So, type: public A opening and closing brackets open the curly brackets press Enter.
02:51 Then type: System dot out dot println within brackets and double quotes Constructing object of type A semicolon.
03:10 Then type: System dot out dot println within brackets and double quotes The value of a is plus a semicolon.
03:35 Now save this file.
03:44 Inside class NonStaticTest in Eclipse let us create an object of the class A.
03:53 So, type: A space a1 equal to new space A opening and closing brackets semicolon.
04:08 Next line, we will create one more object of class A.
04:12 So, type: A space a2 equal to new space A opening and closing brackets semicolon.
04:25 Now, Save and run the file. So, press Ctrl & S and Ctrl & F11 keys.
04:32 We get the output as follows:
04:35 As we can see when the first object is created, the non-static block is executed.
04:45 Non-static block of an instance of class A and the instance variable 'a' is initialized to 0.
04:53 Only after that the constructor is executed. Constructing object of type A.
05:02 And here, the instance variable is again initialized to 0.
05:07 Then again when the second object is created, the non-static block is executed.
05:16 This process is repeated.
05:20 We can have multiple non-static blocks in a class.
05:25 In this case they execute in the sequence in which they appear in the class.
05:30 We can try that now.
05:34 Include one more block after the first one in class A.
05:43 So, again type inside curly brackets:
05:47 System dot out dot println within brackets and double quotes Second Non static block of an instance of Class A semicolon.
06:08 Then type: System dot out dot println within brackets and double quotes The value of a is plus a semicolon .
06:30 Now, save this file , press Ctrl & S key simultaneously then press Ctrl & F11 to run the program.
06:44 We get the output as follows.
06:48 We see that after the first block is executed, the second is executed.
06:58 Only then the constructor is executed.
07:07 Now you might feel why do we need constructors.
07:10 The answer is we don't need the default constructor.
07:15 But the non-static block cannot be parameterized.
07:18 You cannot have objects taking values from out side.
07:22 So non-static block is not a substitute for constructor.
07:27 So, let us summarize.
07:29 In this tutorial we have learnt
07:32 about non-static block and how to use this block.
07:35 For self assessment: Create a class named B.
07:39 Create a non-static block and a constructor as shown in the tutorial.
07:44 Create an object of class B in the class NonStaticTest already created.
07:49 Check the output.
07:51 To know more about the Spoken Tutorial Project,
07:53 watch the video available at http://spoken-tutorial.org/What_is_a_Spoken_Tutorial.
07:56 It summarizes the Spoken Tutorial project.
08:00 If you do not have good bandwidth, you can download and watch it.
08:03 The Spoken Tutorial project team:
08:06 Conducts workshops using spoken tutorials.
08:08 Gives certificates to those who pass an online test.
08:12 For more details, please write to contact@spoken-tutorial.org
08:18 Spoken Tutorial Project is a part of the Talk to a Teacher project.
08:22 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
08:28 More information on this mission is available at http://spoken-tutorial.org/NMEICT-Intro.
08:37 Thus we have come to the end of this tutorial.
08:40 This is Arya Ratish from IIT Bombay, signing off. Thanks for joining.

Contributors and Content Editors

Arya Ratish, Devisenan, Gaurav, PoojaMoolya, Sandhya.np14, Sneha