Sandhya.np14 at 04:47, 18 May 2020

2020-05-18T04:47:59Z

Jyotisolanki at 07:30, 26 December 2017

2017-12-26T07:30:04Z

Pratik kamble at 10:17, 24 November 2017

2017-11-24T10:17:29Z

Pratik kamble at 10:17, 24 November 2017

2017-11-24T10:17:09Z

Jyotisolanki: Created page with "{| border=1 || '''Time''' || '''Narration''' |- | 00:01 | Welcome to the Spoken Tutorial on '''Static Methods'''. |- | 00:05 | In this tutorial we will learn: What are ''..."

2017-09-15T06:15:34Z

Created page with "{| border=1 || '''Time''' || '''Narration''' |- | 00:01 | Welcome to the Spoken Tutorial on '''Static Methods'''. |- | 00:05 | In this tutorial we will learn: What are ''..."

New page

{| border=1
|| '''Time'''
|| '''Narration'''

|-
| 00:01
| Welcome to the Spoken Tutorial on '''Static Methods'''.

|-
| 00:05
| In this tutorial we will learn: What are '''static methods''' , Defining '''static methods'''.

|-
| 00:12
|Difference between '''instance methods''' and '''static methods''' and How to use '''static methods'''.

|-
| 00:20
|Here we are using '''Ubuntu 14.04''' , '''JDK 1 .7''' and ,'''Eclipse 4.3.1'''

|-
| 00:31
|To follow this tutorial, You must have knowledge of basics of '''Java''' and '''Eclipse IDE'''.

|-
| 00:38
|You should also have the knowledge of '''instance variables''', '''methods''' and '''static variables''' in '''Java'''.

|-
| 00:45
|If not, for relevant '''Java''' tutorials, please visit the link shown.

|-
| 00:50
|A '''static method''' is a '''method''' which is associated with the entire '''class'''.

|-
| 00:56
|It is also called a '''class method''' and is declared using the '''static keyword'''.

|-
| 01:02
|'''Static methods''' are usually used to handle '''static variables'''.

|-
| 01:07
|Now we will switch to '''Eclipse''' and create a new project called '''StaticMethodDemo'''.

|-
| 01:14
|Inside this project we will create the necessary '''classes''' to demonstrate the usage of '''Static methods'''.

|-
| 01:21
|We will create a new class '''StudentEnroll'''.

|-
| 01:25
|Let us see how to use '''static methods''' with an example.

|-
| 01:30
|The example is very similar to the one which is used in the '''Static Variable''' tutorial.

|-
| 01:37
|Here again we are representing the '''StudentEnroll class'''.

|-
| 01:42
|Recall that the variables '''name''' and '''id''' are handled as '''instance variable'''s.

|-
| 01:48
|Here the variables '''organization''' and '''total count''' are common to the entire '''class'''.

|-
| 01:54
|So they can be treated as '''static variables'''.

|-
| 01:58
|Now type the following code to represent the '''StudentEnroll class'''.

|-
| 02:03
|Note that there are two '''static variables count''' and '''orgname'''.

|-
| 02:08
|Also note that '''orgname''' is not a '''static constant''' rather it is normal '''static variable'''.

|-
| 02:15
|The '''static variable orgname''' is initialized as '''“IIT Bombay”'''.

|-
| 02:21
|Now click on '''Source''' -> and select '''Generate Constructor using Fields'''.

|-
| 02:27
| Delete the '''super''' keyword from the generated code.

|-
| 02:32
|Inside the '''constructor''', type '''count ++ semicolon''' So, the '''count''' value is incremented every time an '''object''' is created.

|-
| 02:36
|So, the '''count''' value is incremented every time an '''object''' is created.

|-
| 02:42
|Now we will add a method '''showData'''( ) to this class to print the values of the variables.

|-
| 02:48
|So type '''public void showData'''( ).

|-
| 02:51
|Within brackets type the following code to print the values of '''id''', name and '''organisation name'''.

|-
| 02:58
|Now we will '''add the static method setOrgName'''.

|-
| 03:03
|Type the following code.

|-
| 03:05
|The '''setOrgName method''' represented here is a static method which can modify the value of '''orgname'''.

|-
| 03:13
|Any '''method''' which is used to handle '''static variables''' can be defined as a '''static method'''.

|-
| 03:19
|Now let us explore the differences between '''instance method''' and '''static method'''.

|-
| 03:25
|'''Instance methods''' can access '''static variables'''.

|-
| 03:29
|Whereas a '''static method''' can directly access and modify only '''static variables'''.

|-
| 03:35
|'''Instance methods''' are invoked only by an '''object'''.

|-
| 03:39
|Whereas a '''static method''' can be invoked directly without creating an '''object'''.

|-
| 03:45
|We cannot use '''‘this’''' and '''‘super’''' keyword inside a '''static method'''.

|-
| 03:50
|This is because these '''keywords''' refer to the instance of a particular '''class'''.

|-
| 03:56
|In a static context, we can’t refer to instances of a '''class'''.

|-
| 04:01
|Let us see what happens if we try to access an '''instance variable''' directly inside this '''static method'''.

|-
| 04:09
|Type, '''id= “newid” semicolon'''

|-
| 04:13
|Now an error comes up in '''Eclipse'''.

|-
| 04:17
|It indicates that an '''instance variable''' cannot be accessed directly inside a '''static method'''.

|-
| 04:23
|So let us comment this line and proceed.

|-
| 04:27
|Now we will add one more '''static method showOrgData'''.

|-
| 04:31
|These statements print the values of '''orgname''' and '''count'''.

|-
| 04:36
|Now right click on the '''default package''', click '''New-> Class''' and then type the name as '''Demo'''.

|-
| 04:44
|Inside this '''class''' we will have the '''main method'''.

|-
| 04:48
|So type '''main''' and then press Ctrl+space to generate the '''main method'''.

|-
| 04:54
|We will create a few objects of '''StudentEnroll''' class to represent student enrollments.

|-
| 05:01
|So type the following code to create 3 objects '''s1, s2''' and '''s3'''.

|-
| 05:08
|Now let us invoke the '''showData''' method to print the enrollment details.

|-
| 05:12
|Type the following code to invoke '''showData''' method on '''s1, s2''' and '''s3'''.

|-
| 05:19
|Let us also invoke the '''method showOrgData''' to print the values of '''orgname''' and '''count'''.

|-
| 05:27
|Since it is a '''static method''' we can invoke it directly using its '''class''' name.

|-
| 05:31
|To do so, type this code.

|-
| 05:34
|Now let us run the '''Demo''' program.

|-
| 05:37
|We can see that the values of the variables corresponding to '''s1''' i.e '''IT101, ADIL''' and '''IIT BOMBAY''' gets printed.

|-
| 05:47
|Similarly the values corresponding to '''s2''' and '''s3''' are also printed.

|-
| 05:53
|Note that the value of '''orgname ie IIT BOMBAY''' is common for '''s1, s2''' and '''s3'''.

|-
| 06:02
|'''orgname''' and '''count''' are printed separately by the '''static method showOrgData'''.

|-
| 06:08
|Note that the organisation name is printed as '''IIT Bombay'''.

|-
| 06:13
|The value of the number of student enrollments is printed as '''3''', as we have already created 3 objects.

|-
| 06:21
|A '''static method''' can be invoked directly by the '''class''' name itself.

|-
| 06:26
|Now let us invoke the '''static method setOrgName'''.

|-
| 06:30
|We will change the organisation name from '''“IIT Bombay”''' to '''“IIT Mumbai”'''.

|-
| 06:36
| So type the following code.

|-
| 06:38
|Now let us once again invoke the '''showData''' method on '''s1, s2''' and '''s3''' to print the enrollment details.

|-
| 06:47
|For that type the following code again.

|-
| 06:50
|Once again, let us invoke the '''method showOrgData''' to print the values of '''orgname''' and '''count'''.

|-
| 06:58
|To do so, type this code.

|-
| 07:00
|Now run the '''Demo''' program again.

|-
| 07:03
|We can see that the organisation name is changed to '''“IIT Mumbai”'''.

|-
| 07:08
|Let us come back to slides.

|-
| 07:11
|'''Object references''' can be passed to a '''static method'''.

|-
| 07:15
|This way a '''static method''' can access the '''instance variables''' of that particular '''object'''.

|-
| 07:22
|Let us try it in our code. Switch to '''Eclipse '''and go to the '''StudentEnroll class'''.

|-
| 07:30
|Now in the '''setOrgName method''', pass another '''argument''' as an '''object''' of '''StudentEnroll class'''.

|-
| 07:38
|So after '''String org''', type comma '''StudentEnroll s'''

|-
| 07:45
|Now inside this '''method''', uncomment '''id = "newid"'''

|-
| 07:50
|And instead of id, '''type s.id'''

|-
| 07:54
|Now go to the '''Demo class'''.

|-
| 07:56
|Let us modify the '''function call''' to '''setOrgName method''' by passing the '''StudentEnroll object s1'''.

|-
| 08:05
|So here, after '''“IIT Mumbai”''', type comma '''s1'''.

|-
| 08:10
|Now run the '''Demo''' program again.

|-
| 08:12
|We can see that the value of id for s1 has changed to '''“newid”'''.

|-
| 08:19
|Let us summarize. In this tutorial we have learnt about

|-
| 08:24
|What is a '''static method''' and when it is used

|-
| 08:28
|How to differentiate '''static methods''' and '''instance methods''' and

|-
| 08:33
|How to create and invoke '''static methods'''

|-
| 08:37
|This assignment is a continuation of the '''Static variable''' assignment.

|-
| 08:42
|Make sure that you have completed the '''Static variable''' assignment.

|-
| 08:47
|We will highlight only the modifications here.

|-
| 08:50
|Here we have a variable to represent '''“status”'''.

|-
| 08:55
|It is used to indicate whether the car is '''“in”''' for service or '''“out”''' after service

|-
| 09:01
|We will also have another variable to represent '''No of cars out after Service'''.

|-
| 09:08
|Define a '''method service( Car c)''' which updates the status to ”out”.

|-
| 09:13
|Accordingly it modifies the values for

|-
| 09:17
|'''No of Cars in''' for Service '''No of Cars out''' after Service

|-
| 09:21
|Also define a method '''show'''( ) to print all the car details.

|-
| 09:26
|As before, we need to perform the following as listed.

|-
| 09:30
|Note that we have to identify and define the '''static method''' as required.

|-
| 09:35
|Also create a '''Demo class'''.

|-
| 09:38
|Inside the '''main method''', Create a few objects of '''CarService.'''

|-
| 09:43
|Invoke the '''service( ) method''' on some of them.

|-
| 09:47
|Invoke the '''show( ) method''' using all the objects and verify the results.

|-
| 09:52
|The video at the following link summarizes the '''Spoken Tutorial Project'''.

|-
| 09:57
|Please download and watch it.

|-
| 09:59
|The '''Spoken Tutorial Project''' team Conducts workshops using spoken tutorials and Gives certificates on passing the online tests

|-
| 10:08
|For more details, please write to us.

|-
| 10:11
|'''Spoken Tutorial Project is''' funded by the NMEICT, MHRD, Government of India.

|-
| 10:18
|More information on this Mission is available at the link shown.

|-
| 10:22
|This script has been contributed by: '''Dept. of Information Technology, Amal Jyothi College of Engineering'''.

|-
| 10:30
|This is Priya from IIT Bombay, thanks for joining.

|}

@@ Line 333: / Line 333: @@
 |-
 |  07:50
-|And instead of id, '''type s.id'''
+|And instead of id,type ''' s.id'''
 |-

← Older revision		Revision as of 10:17, 24 November 2017
Line 107:		Line 107:
	\|Inside the '''constructor''', type '''count ++ semicolon''' So, the '''count''' value is incremented every time an '''object''' is created.		\|Inside the '''constructor''', type '''count ++ semicolon''' So, the '''count''' value is incremented every time an '''object''' is created.

−	\|-
−	~~\| 02:36~~
−	~~\|So, the '''count''' value is incremented every time an '''object''' is created.~~

	\|-		\|-

@@ Line 9: / Line 9: @@
 |-
 |  00:05
-| In this tutorial we will learn:  What are '''static methods''' , Defining '''static methods'''.
+| In this tutorial we will learn:  what are '''static methods''' , defining '''static methods'''.
 |-
 |  00:12
-|Difference between '''instance methods''' and '''static methods''' and  How to use '''static methods'''.
+|difference between '''instance methods''' and '''static methods''' and  how to use '''static methods'''.
 |-
 |  00:20
-|Here we are using  '''Ubuntu 14.04'''   , '''JDK 1 .7''' and  ,'''Eclipse 4.3.1'''
+|Here we are using  '''Ubuntu 14.04''', '''JDK 1 .7''' and  '''Eclipse 4.3.1'''
 |-
 |  00:31
-|To follow this tutorial,  You must have knowledge of basics of '''Java''' and '''Eclipse IDE'''.
+|To follow this tutorial,  you must have knowledge of basics of '''Java''' and '''Eclipse IDE'''.
 |-

@@ Line 106: / Line 106: @@
 |  02:32
 |Inside the '''constructor''', type '''count ++ semicolon'''  So, the '''count''' value is incremented every time an '''object''' is created.
 |-

Java/C3/Static-Methods/English-timed - Revision history

Sandhya.np14 at 04:47, 18 May 2020

Jyotisolanki at 07:30, 26 December 2017

Pratik kamble at 10:17, 24 November 2017

Pratik kamble at 10:17, 24 November 2017

Jyotisolanki: Created page with "{| border=1 || '''Time''' || '''Narration''' |- | 00:01 | Welcome to the Spoken Tutorial on '''Static Methods'''. |- | 00:05 | In this tutorial we will learn: What are ''..."