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 errors 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]
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 * 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 ErrorFree and select methods stubs public static void main.
01:37 Let us minimize the package explorer. Remove the comments and add the print statement with a 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 error and hence there is a 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 There is only one error now which says: Helloworld 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 is gone and 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, there is a 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.
05:20 Also notice that the word errorfreeis underlined in red colour.
05:29 Eclipse 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 errorfree.
05:43 The fix that we are looking for 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 there 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 the 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 errors 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 summarizes 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