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 tutorial on Errors and Debugging using Eclipse.
Slide 2 Learning Objectives	In this tutorial,we are going to learn what are the possible error while writing a simple Java Program, how to identify those errors and rectify 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 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	In a simple Java program, the typical errors could be. {Pause for a few seconds} Missing semicolon(;) Missing double quotes(" ") around the message Mis-match of filename and classname and Typing the print statement in lower-case We shall write a program and then make each of these errors and see what happens 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 project used for the HelloWorld tutorial We shall create a new class in the project and use it New Class. Let us name the class Error Free and select methods stubs public static Void main Let us minimise the package explorer. Remove the comments and add the print statement to the 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.println line has an errors and hence their is the red cross mark on the left.
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 is syntax error insert semi-colon to complete block statements This is because we have to end every statement of a Java program with a semicolon.
Type ;	So, let us insert semicolon at the end of the statement. Save the file with Ctrl s.
Point back to the cross mark	notice that once you add a semi-colon and add a file the first error is gone. .
Pointing to the second error.	their is only one error that says; hello world cannot be resolved to a variable, which means to display any message on the console the message has to be included in double quotes. 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, Ctrl s to Save. We see that the red cross mark have gone and the program is error free. So let us run the program and see what happens.
Run the program	Run as 'Java applications
Output: HelloWorld	We see that the message has been 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 happens usually on Eclipse. This is because we use the New Class wizard to create a file and eclipse creates a file automatically
Change ErrorFree to errorfree.	But if we create a Java file outside of Eclipse and add it to a project, their is the chance of the error So let us stimulate the error , by changing the class name.
Point to the file ErrorFree.java in Project Explorer Portlet	Since Java is case-sensitive, now the class name and file name do not match .
Mouse over the red cross mark	Notice that , there is a red cross mark on the left margin.
Mouse over the error message	And error message reads The public type errorfree must be defined in its own file. I
Mouse over the class name errorfree	Also notice that the word errorfree underlined in red colour.
Mouse over the fixes available	Eclipse offers intelligent fixes and we have 2 fixes available here
Point to the first fix.	The first one is rename compilation unit to errorfree java
Point to the second fix.	The second one is to 'rename type to errorfree.
Click Rename Change errorfree to ErrorFree	The fix thatwe are looking to is the second one.And we see that once you rename the file the class back to errorfree the error here is missing.
Change the word System to system	The next error 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 notice that heir is the red-cross mark And error message reads system cannot be resolved. This means Java is expecting a class or object or a variable by the name system. But there is nothing like system object in the code.
Mouse over the system word	Let us look at the possible fixes..
Click on Change to 'System' (java.lang) Change s to S	there are 11 fixes out of these fix that we are looking for is the eighth option Change to 'System' (java.lang) You can see that once we change it to capital S the error is missing.
	here is how you identify errors in Java using eclipse and rectify them
Minimize Eclipse and maximize slides Slide 6 Summary	This brings us to the end of this tutorial. In this tutorial we have seen 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, find out the error in the code given below and fix them
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