PoojaMoolya at 06:24, 17 June 2014

2014-06-17T06:24:34Z

Pravin1389 at 05:20, 13 June 2014

2014-06-13T05:20:11Z

Sneha at 18:36, 7 May 2013

2013-05-07T18:36:38Z

Sneha at 17:45, 7 May 2013

2013-05-07T17:45:49Z

Show changes

Chandrika: Created page with ''''Title:''' Finding Errors and Debugging using Eclipse '''Author: '''TalentSprint '''Keywords: '''Video tutorial, Errors, debugging, eclipse, java {| style="border-spacing:0…'

2012-11-27T10:07:02Z

Created page with ''''Title:''' Finding Errors and Debugging using Eclipse '''Author: '''TalentSprint '''Keywords: '''Video tutorial, Errors, debugging, eclipse, java {| style="border-spacing:0…'

New page

'''Title:''' Finding Errors and Debugging using Eclipse

'''Author: '''TalentSprint

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

{| style="border-spacing:0;"
| style="border:0.035cm solid #000000;padding:0.097cm;"| '''Visual Clue'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| '''Narration '''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 1

'''Welcome'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| Welcome to the spoken tutorial on '''Errors and Debugging using Eclipse.'''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 2

'''Learning Objectives'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 3

'''Software Versions'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| For this tutorial we are using

Ubuntu 11.10,

Eclipse 3.7

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 4

'''Prerequisites'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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 [http://spoken-tuitorial.org/ ][http://spoken-tuitorial.org/ http][http://spoken-tuitorial.org/ ://][http://spoken-tuitorial.org/ spoken][http://spoken-tuitorial.org/ -][http://spoken-tuitorial.org/ tuitorial][http://spoken-tuitorial.org/ .][http://spoken-tuitorial.org/ org]

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 5

'''Possible Errors'''

* Missing semicolon(;)
* Missing double quotes(" ") Mis-match of filename and classname
* Typing the print statement in lower-case''' '''

| style="border:0.035cm solid #000000;padding:0.097cm;"| 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'''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| '''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<nowiki>[]) </nowiki>'''

'''{ '''

'''System.out.println(Hello World) '''

'''} '''

'''}'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Point to the '''red cross mark''' on the margin, left of the line '''Sytem.out...'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.'''

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Hover mouse over the '''cross mark'''.
| style="border:0.035cm solid #000000;padding:0.176cm;"| The list of errors is displayed by hovering the mouse over the '''cross mark.'''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Pointing at the cross mark on the left of the line '''System.out.println'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Type '''<nowiki>;</nowiki>'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| So, let us insert the ''semicolon'' at the end of the statement.

'''Save''' the file.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Point back to the '''cross mark'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Pointing to the '''second error.'''

| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| '''Type “ ” '''on both ends of HelloWorld
| style="border:0.035cm solid #000000;padding:0.176cm;"| Let us add double quotes before and after the message, '''HelloWorld.'''

'''Save''' the file.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| '''Run the program'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Output:

'''HelloWorld'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| We see that the message '''HelloWorld''' is printed on the console.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Open the '''New Java Class Wizard.'''

Type the '''class name''' and '''Finish'''

Point to the created '''file name''' and '''class name.'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Change '''ErrorFree''' to '''errorfree.'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| 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'''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Point to the file '''ErrorFree.java''' in '''Project Explorer Portlet'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Mouse over the '''red cross mark'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| As we can see, there is a '''red cross mark '''on the left of the margin.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Mouse over the '''error message'''

| style="border:0.035cm solid #000000;padding:0.097cm;"| The message reads '''The public type errorfree must be defined in its own file.'''

It means, the classname and the filename are different.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Mouse over the class name '''errorfree'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| '''Eclipse '''also offers intelligent fixes.

Notice that the class name is''' underlined in red colour. '''

Let us mouse over the underline.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Mouse over the fixes available
| style="border:0.035cm solid #000000;padding:0.176cm;"| We can see the error message and also that there are '''2 fixes available'''

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Point to the first fix.
| style="border:0.035cm solid #000000;padding:0.176cm;"| The first one is renaming the file to suit the class name.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Point to the second fix.
| style="border:0.035cm solid #000000;padding:0.176cm;"| The second one is to rename the class name to suit the file name.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Click '''Rename'''

Change''' errorfree to ErrorFree'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| Here, we shall click the second option and rename the class name.

As we can see, now the red mark disappears.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Change the word '''System '''to''' system'''
| style="border:0.035cm solid #000000;padding:0.176cm;"| 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'''.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Point to the '''red cross mark'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"| Mouse over the '''system''' word
| style="border:0.035cm solid #000000;padding:0.176cm;"| Let us look at the possible fixes..

It says '''11 quick fixes available.'''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Click on '''Change to 'System' (java.lang)'''

Change '''s '''to '''S'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.176cm;"|
| style="border:0.035cm solid #000000;padding:0.176cm;"| This is how we identify errors depending on the error messages and rectify them using '''Eclipse'''.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| '''Minimize Eclipse and maximize slides'''

Slide 6

'''Summary'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| 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'''.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 7

'''Assignment'''
| style="border:0.035cm solid #000000;padding:0.097cm;"| As an assignment for this tutorial, identify and fix the errors in the code given below.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 8'''About the Spoken Tutorial Project'''

* Watch the video available at[http://spoken-tutorial.org/What_is_a_Spoken_Tutorial ][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial http][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial ://][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial spoken][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial -][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial tutorial][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial .][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial org][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial /][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial What][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial is][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial a][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial Spoken][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial _][http://spoken-tutorial.org/What_is_a_Spoken_Tutorial Tutorial]

* It summarises the Spoken Tutorial project

* If you do not have good bandwidth, you can download and watch it

| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 9'''Spoken Tutorial Workshops'''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 [mailto:contact@spoken-tutorial.org contact][mailto:contact@spoken-tutorial.org @][mailto:contact@spoken-tutorial.org spoken][mailto:contact@spoken-tutorial.org -][mailto:contact@spoken-tutorial.org tutorial][mailto:contact@spoken-tutorial.org .][mailto:contact@spoken-tutorial.org org]

| style="border:0.035cm solid #000000;padding:0.097cm;"| 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.'''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 10'''Acknowledgement'''

* 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 http][http://spoken-tutorial.org/NMEICT-Intro ://][http://spoken-tutorial.org/NMEICT-Intro spoken][http://spoken-tutorial.org/NMEICT-Intro -][http://spoken-tutorial.org/NMEICT-Intro tutorial][http://spoken-tutorial.org/NMEICT-Intro .][http://spoken-tutorial.org/NMEICT-Intro org][http://spoken-tutorial.org/NMEICT-Intro /][http://spoken-tutorial.org/NMEICT-Intro NMEICT][http://spoken-tutorial.org/NMEICT-Intro -][http://spoken-tutorial.org/NMEICT-Intro Intro]

| style="border:0.035cm solid #000000;padding:0.097cm;"| '''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'''

|-
| style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 11'''About the contributor'''

* This tutorial has been contributed by '''TalentSprint'''
* '''www.talentsprint.com'''

* Thanks for joining

| style="border:0.035cm solid #000000;padding:0.097cm;"| This tutorial has been contributed by '''TalentSprint'''.

Thanks for joining.

|}

@@ Line 220: / Line 220: @@
 |-
 | style="border:0.035cm solid #000000;padding:0.176cm;"| Mouse over the fixes available
-| style="border:0.035cm solid #000000;padding:0.176cm;"| ''' Java offers intelligent fixes  and we have 2 fixes available here
+| style="border:0.035cm solid #000000;padding:0.176cm;"| ''' Eclipse offers intelligent fixes  and we have 2 fixes available here

@@ Line 14: / Line 14: @@
 '''Welcome'''
-| style="border:0.035cm solid #000000;padding:0.097cm;"| Welcome to the spoken tutorial on '''Errors and Debugging using Eclipse.'''
+| style="border:0.035cm solid #000000;padding:0.097cm;"| Welcome to the   tutorial on '''Errors and Debugging using Eclipse.'''
 |-
@@ Line 20: / Line 20: @@
 '''Learning Objectives'''
-| style="border:0.035cm solid #000000;padding:0.097cm;"| In this tutorial, you are going to  learn
+| style="border:0.035cm solid #000000;padding:0.097cm;"| In this tutorial,we  are going to  learn
-xwhat are the possible error about the possible errors in a typical '''Java '''Program,
+what are the possible error  while writing a  simple '''Java '''Program,
-−
-how to identify them and
-−
-how to correct them using Eclipse.
 |-
 | style="border:0.035cm solid #000000;padding:0.097cm;"| Slide 3
@@ Line 65: / Line 63: @@
 * Missing semicolon(;)
-* Missing double quotes(" ")
+* Missing double quotes(" ") around the message
 * Mis-match of filename and classname and
 * Typing the print statement in lower-case

@@ Line 7: / Line 7: @@
 {| style="border-spacing:0;"
-| style="border:0.035cm solid #000000;padding:0.097cm;"| '''Visual Clue'''
+| style="border:0.035cm solid #000000;padding:0.097cm;"| '''Visual Cue'''
 | style="border:0.035cm solid #000000;padding:0.097cm;"| '''Narration '''

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

PoojaMoolya at 06:24, 17 June 2014

Pravin1389 at 05:20, 13 June 2014

Sneha at 18:36, 7 May 2013

Sneha at 17:45, 7 May 2013

Chandrika: Created page with ''''Title:''' Finding Errors and Debugging using Eclipse '''Author: '''TalentSprint '''Keywords: '''Video tutorial, Errors, debugging, eclipse, java {| style="border-spacing:0…'