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

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Time Narration
00:01 Welcome to the tutorial on Errors and Debugging using Eclipse.
00:07 In this tutorial,we are going to learn
00:10 what are the possible error while writing a simple Java Program,
00:14 how to identify those errors and rectify them using eclipse.
00:20 For this tutorial we are using

Ubuntu 11.10 and

Eclipse 3.7

00:27 To follow this tutorial you must know
00:30 how to create and run a Java Program in Eclipse.


00:33 If not, for relevant tutorial please visit our website as shown [1]http://spoken-tuitorial.org
00:41 In a simple Java program, the typical errors could be.
00:45 Missing semicolon(;)
00:47 Missing double quotes(" ") around the message
00:50 Mis-match of filename and classname and
00:52 And Typing the print statement in lower-case
00:55 We shall write a program and then make each of these errors and see what happens in Eclipse
01:04 Here we have the Eclipse IDE and the project used for the HelloWorld tutorial
01:11 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
01:37 Let us minimise the package explorer. Remove the comments and add the print statement to the few errors
02:23 In Eclipse, the line which has the error will be indicated with a red cross mark on the left margin.


02:35 In this case, the System.out.println line has an errors and hence their is the red cross mark on the left.
02:44 The list of errors is displayed by hovering the mouse over the cross mark.
02:51 The first error displayed is syntax error insert semi-colon to complete block statements
02:58 This is because we have to end every statement of a program with a semicolon.



03:03 So, let us insert semicolon at the end of the statement.


03:08 Save the file with Ctrl s.


03:16 notice that once we add the semi-colon and save the file, the first error is gone.


03:21 their is only one error now which 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.


03:37 Without the quotes, Java thinks that HelloWorld is the name of a variable.



03:41 Let us add double quotes before and after the message,
03:55 Ctrl s to Save. We see that the red cross mark have gone an d the program is error free. So let us run the program and see what happens.
04:10 Run as 'Java applications


04:15 We see that the message has been printed on the console.
04:22 Let us look at the next error.


04:25 It happens due to a mismatch of file name and class name.


04:29 It does not happens usually on Eclipse.


04:31 This is because we use the New Class wizard to create a file and eclipse


04:39 creates a file automatically
04:41 But if we create a Java file outside of Eclipse and add it to a project, their is the chance of the error


04:47 So let us stimulate the error , by changing the class name.


04:59 Since Java is case-sensitive, now the class name and file name do not match .


05:09 Notice that , there is a red cross mark on the left margin.
05:14 And error message reads The public type errorfree must be defined in its own file.


I

05:20 Also notice that the word errorfreeis underlined in red colour.
05:29 Java offers intelligent fixes and we have 2 fixes available here


05:35 The first one is rename compilation unit to errorfree java
05:39 The second one is 'rename the type to error.
05:43 The fix that we 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.


06:03 The next error happens due to typing mistakes in the print statement.


06:09 Let us replace the capital S with a small s.
06:15 We notice that their is the red-cross mark


06:18 And error message reads system cannot be resolved.


06:23 This means, Java is expecting a class or object or a variable by the name system.


06:28 But there is nothing like system object in the code.
06:33 So let us look at the possible fixes..
06:39 there are 11 fixes out of these, fix that we are looking for is the eighth option


06:48 Change to 'System' (java.lang)


06:58 You can see that once we change it to capital S the error is missing.
07:06 here is how you identify errors in Java using eclipse and rectify them
07:15 This brings us to the end of this tutorial.
07:18 In this tutorial we have seen
07:20 what are the typical errors while writing a Java program and
07:23 how to identify them and rectify them using Eclipse.
07:30 As an assignment for this tutorial, find out the error in the code given below and fix them
07:39 To know more about the Spoken Tutorial project,
07:42 Watch the video available at the following link, It summarises the project.
07:48 If you do not have good bandwidth, you can download and watch it


07:53 The Spoken Tutorial Team conducts workshops using spoken tutorials.


07:57 Gives certificates for those who pass an online test. For more details, please write to contact AT spoken HYPHEN tutorial DOT org.
08:07 Spoken Tutorial Project is a part of the Talk to a Teacher project.


08:11 It is supported by the National Mission on Education through ICT, MHRD, Government of India.


08:17 More information on this Mission is available at spoken HYPHEN tutorial DOT org SLASH NMEICT HYPHEN Intro
08:23 This tutorial has been contributed by TalentSprint.

Thanks for joining.



Contributors and Content Editors

Gaurav, Madhurig, PoojaMoolya, Pravin1389, Sandhya.np14, Sneha