Java/C2/First-Java-Program/English-timed

Time	Narration
00:02	Welcome to the Spoken Tutorial on getting started with the First java program.
00:09	In this tutorial, we will learn:
00:11	* To create a simple Java program
00:14	* To compile the program
00:16	* To run the program and
00:19	* About the naming conventions followed in Java.
00:23	Here we are using Ubuntu version 11.10 and jdk 1.6.
00:32	To follow this tutorial, JDK 1.6 must be installed on your system.
00:39	If not, for relevant tutorial, please visit our website which is as shown.
00:46	Alright, now let us write our first Java program.
00:51	For that, you need a Terminal and you need a Text Editor.
00:56	I am using gedit as my Text Editor.
01:01	In the text editor, we will first create the class HelloWorld.
01:06	So, type: class HelloWorld. "HelloWorld" is the name of the class.
01:17	And, open curly bracket. Enter and close curly bracket.
01:24	The code between these two curly brackets will belong to the class 'HelloWorld'.
01:33	Now save the file by clicking on Save icon at the top.
01:37	It is a good practice to save the file frequently.
01:43	so Save As Dialog box appears.
01:46	Browse the location where you want to save your file.
01:51	Here, in the home directory, I will create a folder.
01:57	Let us name it Demo and press Enter.
02:02	Then, inside this folder we will save the file.
02:08	In the Name text-box, type the name of the class.
02:13	In Java, the name of the class and the file name should be same.
02:20	Recall that we created class HelloWorld.
02:25	So, we will save the file as HelloWorld dot java.
02:33	Dot Java (.java) is the file extension given to the Java file.
02:39	Then click on Save button. So the file is now saved.
02:47	Inside the class, we write the main method.
02:53	So, type:
02:54	public static void main parentheses inside parentheses String arg square brackets.
03:10	main function marks the starting point of the program.
03:15	We will describe public, static, void and String in a future tutorial.
03:23	Then once again, open curly bracket,
03:27	press Enter and close curly bracket.
03:32	The code between these two curly brackets will belong to the main method.
03:41	We will now write a code to display a line on the Terminal.
03:46	So, inside main method, type: System dot out dot println parentheses semicolon.
03:59	This is the statement used to print a line.
04:05	Semicolon is used to terminate a line.
04:10	Now let us tell Java, what to print.
04:13	So, within parentheses in double quotes, type: My first Java program exclamation mark.
04:30	Let us save the file by clicking on Save icon.
04:36	Let's go to the Terminal.
04:38	Make sure that you are in the directory where you saved your 'HelloWorld.java'
04:46	Remember that I am in my home directory.
04:50	So, type: cd Space Demo and hit Enter.
04:56	ls, press Enter.
04:59	We see 'HelloWorld.java' file present in the 'Demo' folder.
05:06	Let's compile this file. So, type: javac Space HelloWorld dot java and hit Enter.
05:21	This compiles the file that we have created.
05:25	Alright, now the file is compiled as we see no error.
05:30	We can see HelloWorld.class file created.
05:36	This file can run anywhere.
05:38	That is, on any Operating System.
05:41	We do not need java compiler as well.
05:45	Hence, java is rightly described as “write once, run anywhere.”
05:51	So, after successful compilation, run the program using the command,
05:56	java(This time no c) space HelloWorld(and no dot java extension) and hit Enter.
06:07	You will get the output My first java program!
06:13	So, we have written our first java program. Let us go back to the editor.
06:22	Now, remove the semicolon which is at the end of the statement.
06:27	Click on Save icon.
06:29	Let us go back to the Terminal.
06:33	Run the command javac HelloWorld dot java.
06:41	The compiler gives an error.
06:44	It says, a semicolon (;) is expected on the fifth line.
06:52	The up-arrow points to the error statement.
06:57	Let us go back to the Editor.
07:01	In Java, all statements are terminated with semicolons.
07:06	So, go to the fifth line and add a semicolon.
07:13	Click on the Save icon. It is necessary to save the file before compiling.
07:22	Let us go back to the Terminal.
07:25	Compile the file using javac HelloWorld dot java.
07:32	The file is successfully compiled as we see no errors.
07:36	Now, run the program using the command java HelloWorld and
07:45	we see the output My first Java program!
07:49	This is how you handle errors in java.
07:54	As the series progresses, we will learn more about the errors.
08:02	We now see what are the naming conventions in java.
08:06	The class name should be in CamelCase
08:10	which means each new word begins with an upper case.
08:14	Example: class HelloWorld, class ChessGame.
08:19	So, 'H' of 'Hello' and 'W' of 'World' are in uppercase.
08:25	Similarly, 'C' and 'G' of 'ChessGame' respectively are in uppercase.
08:31	The method name should be the mixed case.
08:35	which means that the first word should begin with a lowercase.
08:39	and all new words followed should begin with an uppercase.
08:44	Also the method name should be a verb.
08:48	For Example: showString(), main(), goToHelp(). Here 's' of show is in lowercase while 'S' of string is in uppercase.
09:02	The variable name should not begin with digits.
09:06	We cannot use keywords for our class, method or variable name.
09:13	For example: cannot use keywords like public, private, void, static and many more.
09:22	So in this tutorial, we have learnt to write, compile and run a simple java program.
09:30	We also saw the naming conventions followed in java.
09:35	For self assessment, write a simple java program to print "Java file name and class name should be same".
09:47	To know more about the Spoken Tutorial Project,
09:50	watch the video available at [1]
09:58	It summarizes the Spoken Tutorial project.
10:02	If you do not have good bandwidth, you can download and watch it.
10:08	The Spoken Tutorial Project team:
10:10	Conducts workshops using spoken tutorials.
10:13	Gives certificates to those who pass an online test.
10:17	For more details, please write to contact@spoken-tutorial.org
10:25	Spoken Tutorial project is a part of the Talk to a Teacher project.
10:30	It is supported by the National Mission on Education through ICT, MHRD, Government of India.
10:38	More information on this mission is available at: [2].
10:49	We have come to the end of this tutorial.
10:51	Thanks for joining.
10:53	This is Prathamesh Salunke, signing off. Jai Hind.

Contributors and Content Editors

Arya Ratish, Ashwini, Gaurav, Kavita salve, PoojaMoolya, Pratik kamble, Priyacst, Sandhya.np14, Sneha, Vasudeva ahitanal