Java/C2/Errors-and-Debugging-in-Eclipse/English

Title: Finding Errors and Debugging using Eclipse

Author: TalentSprint

Keywords: Video tutorial, Errors, debugging, eclipse, java

Visual Clue	Narration
Slide 1 Welcome	Welcome to the spoken tutorial on Errors and Debugging using Eclipse.
Slide 2 Learning Objectives	In this tutorial, you will learn about the possible errors in a typical Java Program, how to identify them and how to correct them using Eclipse.
Slide 3 Software Versions	For this tutorial we are using Ubuntu 11.10, Eclipse 3.7
Slide 4 Prerequisites	To follow this tutorial you must know how to create and run a Java Program in Eclipse. If not, for relevant tutorial please visit our website which is as shown [1]http://spoken-tuitorial.org
Slide 5 Possible Errors Missing semicolon(;) Missing double quotes(" ") Mis-match of filename and classname Typing the print statement in lower-case	When writing a Java program, here is a list of typical errors we are likely to make. {Pause for a few seconds} Missing semicolon(;) Missing double quotes(" ") Mis-match of filename and classname Typing the print statement in lower-case We shall write a program and then make each of these errors and rectify them in Eclipse
Minimize slides and maximize Eclipse {Eclipse should contain the project DemoProject used in previous tutorial} And the file ErrorFree.java with these lines of code. public class ErrorFree { public static void main(String args[]) { System.out.println(Hello World) } }	Here we have the Eclipse IDE and the skeleton required for the rest of the code. We have created a class ErrorFree and added the main method to it. We have a HelloWorld program but with a few errors.
Point to the red cross mark on the margin, left of the line Sytem.out...	In Eclipse, the line which has the error will be indicated with a red cross mark on the left margin. In this case, the System.out line has errors and hence we have red cross mark.
Hover mouse over the cross mark.	The list of errors is displayed by hovering the mouse over the cross mark.
Pointing at the cross mark on the left of the line System.out.println	The first error displayed in the message box says, insert semicolon. This is because we have to end every statement of a Java program with a semicolon.
Type ;	So, let us insert the semicolon at the end of the statement. Save the file.
Point back to the cross mark	Now we see that there is only one error and the semicolon error has been recolved.. Now, let us look at the other errors in the message box.
Pointing to the second error.	The second error says that HelloWorld cannot be resolved. That happens because of missing double quotes. To display any message on our console. It should be placed within the double quotes only. Without the quotes, Java thinks that HelloWorld is the name of a variable.
Type “ ” on both ends of HelloWorld	Let us add double quotes before and after the message, HelloWorld. Save the file.
Run the program	Now we see that the error has been resolved and the program is error free. So let us run the program and see what happens. Press Ctrl + F11 to run.
Output: HelloWorld	We see that the message HelloWorld is printed on the console.
Open the New Java Class Wizard. Type the class name and Finish Point to the created file name and class name.	Let us look at the next error. It happens due to a mismatch of file name and class name. It does not usually happen on Eclipse. This is because we use the New Class wizard to create a class and the wizard creates the file according to the class name.
Change ErrorFree to errorfree.	But if we create a Java file outside of Eclipse and add it to a project, the error can occur. To simulate the error, let us change the class name. I’m changing E to e
Point to the file ErrorFree.java in Project Explorer Portlet	Since Java is case-sensitive, now the class name and file name are different . Class name is errorfree with all letters in lower-case. While file name is ErrorFree.java with E and F in uppercase.
Mouse over the red cross mark	As we can see, there is a red cross mark on the left of the margin.
Mouse over the error message	The message reads The public type errorfree must be defined in its own file. It means, the classname and the filename are different.
Mouse over the class name errorfree	Eclipse also offers intelligent fixes. Notice that the class name is underlined in red colour. Let us mouse over the underline.
Mouse over the fixes available	We can see the error message and also that there are 2 fixes available
Point to the first fix.	The first one is renaming the file to suit the class name.
Point to the second fix.	The second one is to rename the class name to suit the file name.
Click Rename Change errorfree to ErrorFree	Here, we shall click the second option and rename the class name. As we can see, now the red mark disappears.
Change the word System to system	Let us look at the next error. It happens due to typing mistakes in the print statement. Let us replace the capital S with a small s.
Point to the red cross mark	We can see that the cross mark reappears. Let us look at the error message. Mouse over the cross mark. The message says system cannot be resolved. This means Java is expecting a class or object or variable by the name system. But there is nothing like system object or variable in the code.
Mouse over the system word	Let us look at the possible fixes.. It says 11 quick fixes available.
Click on Change to 'System' (java.lang) Change s to S	Out of these, the fix we are looking for is the eighth option. It says Change to 'System' (java.lang) So click on it. And we see that the program is error free again.
	This is how we identify errors depending on the error messages and rectify them using Eclipse.
Minimize Eclipse and maximize slides Slide 6 Summary	We have come to the end of this tutorial. In this tutorial we have learnt what are the typical errors while writing a Java program and how to identify and rectify them using Eclipse.
Slide 7 Assignment	As an assignment for this tutorial, identify and fix the errors in the code given below.
Slide 8About the Spoken Tutorial Project Watch the video available at[2]http://spoken-tutorial.org/What_is_a_Spoken_Tutorial It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it	To know more about the Spoken Tutorial project, Watch the video available at the following link, that summarises the project.Alternatively, you can download and watch it.
Slide 9Spoken Tutorial WorkshopsThe Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates for those who pass an online test For more details, please write to contact@spoken-tutorial.org	The Spoken Tutorial Project Team. Conducts workshops using spoken tutorials. Gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org.
Slide 10Acknowledgement Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at http://spoken-tutorial.org/NMEICT-Intro	Spoken Tutorial Project is a part of the Talk to a Teacher project. Itis supported by the National Mission on Education through ICT, MHRD, Government of India. More information on this Mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro
Slide 11About the contributor This tutorial has been contributed by TalentSprint www.talentsprint.com Thanks for joining	This tutorial has been contributed by TalentSprint. Thanks for joining.

Contributors and Content Editors

Chandrika, PoojaMoolya, Pravin1389, Sneha