Java/C2/Methods/English-timed

Time	Narration
00:02	Welcome to the Spoken Tutorial on methods in java.
00:06	In this tutorial, we will learn:
00:08	* To create a method.
00:10	* And to call a method.
00:13	Here we are using,
00:14	* Ubuntu version 11.10
00:17	* Java Development kit 1.6 and
00:20	* Eclipse 3.7.0
00:24	To follow this tutorial, you must know how to write, compile and run a simple java program in eclipse.
00:32	If not, for relevant tutorials, please visit our website which is as shown. http://www.spoken-tutorial.org
00:40	A java method is a collection of statements that performs a specified operation.
00:46	Let us now write a method.
00:50	So, in the eclipse, I have already created a project Methods.
00:57	In the project, I have created a java class named MethodDemo.
01:06	In the class, outside the main method, we will write a method.
01:13	So, type: void name of the method
01:19	Let us name it as displayMessage parentheses Enter.
01:29	And curly brackets.
01:32	A method can return a value.
01:34	But if you don’t want the method to return a value then the keyword void is used.
01:42	Alright, now inside the curly brackets, let us print a message.
01:47	So, type: System dot out dot println Hello Method.
02:06	So, we have written a method.
02:10	Now, we will call this method.
02:13	So, inside the main method, we will create an object of the class MethodDemo.
02:21	So, MethodDemo object name.
02:26	Let's name it as md =new MethodDemo parentheses semicolon.
02:37	So, we have created an object md of the class MethodDemo using the new operator.
02:48	Now, let us call the method displayMessage.
02:51	So, type: md dot displayMessage();.
03:00	The 'dot' operator is used to call the method.
03:06	Now, let us Run this application by clicking on Run icon.
03:14	We see the output Hello Method on the console.
03:20	Now, let us return an integer instead of void.
03:26	So, type: int.
03:32	Also, make the method public, that is accessible everywhere.
03:37	By default, it is private, that is accessible only within the class where it is written.
03:45	Now, inside the method, type return seven semicolon.
03:55	Remember that we write the return statement at the end of all statements in the method.
04:02	This is because after return statement no other statements are executed.
04:08	Now, inside the main method, at the end, type the 'print' statement.
04:15	So, type: System dot out dot println();
04:23	Within parentheses, we will call the method.
04:28	So, put md dot method inside the parentheses, remove the semicolon.
04:37	This will print the return value of the method.
04:42	Run the application.
04:45	We see in the output, the value 7 is printed.
04:51	Now we will write another method and call this method in displayMessage.
04:59	So, type: public void method name square within parentheses int a.
05:15	Here, we are giving int a as a parameter to our method.
05:20	Now, within curly brackets type: System dot out dot println within parentheses a into a.
05:37	So, we have written a square method
05:40	that will display a square of an integer which is given as a parameter.
05:48	Let us call this method in the displayMessage method.
05:53	So, type: square within parentheses an integer 5 semicolon.
06:07	Run this application.
06:12	We see that the output displays the square of 5 that is 25.
06:19	Now, let us understand the flow of the application.
06:24	The starting point is the main method.
06:29	In the Main method, we have first called the displayMessage.
06:34	So, the control goes to the displayMessage
06:40	and all the statements in the displayMessage are executed.
06:45	The first one is the print statement.
06:50	Then it comes across the square method.
06:54	So the control jumps to the square method.
06:57	The square method takes an integer 5 and returns the square of the integer i.e. 25.
07:06	Then the control goes back to the displayMessage.
07:10	And it returns the value 7.
07:14	Then the control jumps back to the main function.
07:20	Since there are no statements left to execute, in the main method, the application terminates.
07:29	Alright! Now let us make displayMessage as static.
07:35	So, after public type static.
07:40	We see that we cannot call a 'non static' method inside the static method.
07:47	So, we will comment this call.
07:52	Since main is a static method, we can call the static displayMessage inside this.
08:02	Now, for static method, we do not need to create an object.
08:07	So, we will comment this object creation.
08:11	Also we will delete md.
08:18	Run the application.
08:22	We see the output Hello Method and 7.
08:27	We do not see 25 because we have commented the call to square method.
08:34	We can also call method from other class.
08:38	For that, I have created a class Demo.
08:45	Inside the class, create a method.
08:48	So, type: public void show parentheses Enter.
08:56	Inside curly brackets, System dot out dot println
09:07	I am from other class.
09:13	Save the file.
09:16	Go back to MethodDemo class.
09:19	Now we will call this show method, inside the method MethodDemo class.
09:28	For that we need to create the object of the class Demo.
09:22	This is because the show method belongs to the class Demo.
09:38	So, type: Demo d=new Demo parentheses semicolon.
09:48	Then call the method show.
09:54	Lets Run this application.
09:58	We see on the console: I am from other class.
10:04	This is how methods are used in java.
10:09	The method name and the parameters form the signature of the method
10:14	while the curly brackets and the statements form the body of the method.
10:23	So, in this tutorial, we have learnt:
10:25	* To create a method
10:27	* To call a method
10:29	* And different signatures of methods.
10:32	For self assessment, create a method which prints the cube of an integer.
10:38	To know more about the Spoken Tutorial project,
10:41	watch the video available at [1].
10:47	It summarizes the Spoken Tutorial project.
10:50	If you do not have good bandwidth, you can download and watch it.
10:54	The Spoken Tutorial project team:
10:56	Conducts workshops using spoken tutorials.
10:58	Gives certificates to those who have passed an online test.
11:02	For more details, please write to contact@spoken-tutorial.org
11:08	Spoken Tutorial project is a part of the Talk to a Teacher project.
11:12	It is supported by the National Mission on Education through ICT, MHRD, Government of India.
11:18	More information on this mission is available at [2].
11:27	We have come to the end of this tutorial.
11:29	Thanks for joining.
11:30	This is Prathamesh Salunke, signing off. Jai Hind.

Contributors and Content Editors

Arya Ratish, Gaurav, Jyotisolanki, PoojaMoolya, Priyacst, Sandhya.np14, Sneha