KTurtle/C3/Common-Errors-in-KTurtle/English-timed

Time	Narration;
00:01	Welcome to this tutorial on Common Errors in KTurtle.
00:07	In this tutorial, we will learn about
00:10	Syntax errors
00:12	Runtime errors and
00:14	Logical errors
00:17	To record this tutorial I am using,
00:20	Ubuntu Linux OS version 12.04.
00:25	KTurtle version. 0.8.1 beta.
00:31	We assume that you have basic working knowledge of KTurtle
00:36	If not, for relevant tutorials, please visit our website. http://spoken-tutorial.org
00:42	Let's first define, What is an error ?
00:46	Error is a mistake in a program that produces an incorrect or unexpected result.
00:55	First I will explain about "Types of errors".
01:00	Syntax error is a violation of grammatical rules, of a programming language.
01:09	Compilation fails when a program has syntax errors.
01:15	Syntax errors are easy to find and fix.
01:22	For Example:
01:23	Unmatched parentheses, square and curly braces.
01:29	Use of variable that has not been declared.
01:34	Missing quotes in strings.
01:38	Let's open a new KTurtle Application.
01:42	Click on Dash home. In the Search bar, type KTurtle.
01:48	Click on the KTurtle icon.
01:51	Let's begin the tutorial with some types of syntax errors.
01:58	I already have a program in a text editor.
02:02	To explain the error in the program, I will comment part of the code.
02:09	Here, I will comment the line
02:11	$a=ask within double quotes "enter any number and click Ok"
02:19	I will use hash(#) sign to comment the line.
02:23	I will copy the program from text editor and paste it into Kturtle's Editor.
02:31	Pause the tutorial here and type the program into your KTurtle editor
02:37	Resume the tutorial after typing the program.
02:42	Let's click on Run button to run the program
02:47	Compiler shows the following error,
02:50	variable "$a" was used without first being assigned to a value.
02:57	Here the error is in line number 4.
03:02	This is a syntax error. It occured, as the variable 'a' was not declared.
03:10	So I will go to line number 2, remove the comment.
03:14	I will copy the program from text Editor and paste it into KTurtle's editor.
03:23	Let's click on Run button to run the program
03:27	Enter 6 for a value and click OK
03:31	Program runs without errors.
03:35	I will clear the current program from KTurtle editor.
03:38	Type clear command and Run to clean the canvas.
03:43	let's next look at another error.
03:46	I already have a program in a text editor.
03:50	Here the value of "pi" is predefined in KTurtle.
03:54	Let's delete the "$" sign in the program.
03:58	I will copy the program from text editor and paste it into Kturtle's Editor
04:05	Pause the tutorial here and type the program into your KTurtle editor
04:11	Resume the tutorial after typing the program.
04:16	Let's Click on Run button to run the program.
04:19	Complier shows the following error,
04:22	you cannot put “=” here
04:26	This error is in line number 2.
04:30	This is a syntax error it occured, as there is no container of variable.
04:37	Let's go back to the program replace the $ sign.
04:41	I will copy the program from text editor and paste it into KTurtle's Editor
04:49	let's click on Run button to run the program.
04:53	Enter 45 for angle value and click OK
04:57	Program runs without errors.
05:00	Let's remove one of the quotes of the string.
05:05	I will Copy the program from text editor and paste it into KTurtle's Editor
05:12	Click on Run button to run the program
05:15	Complier shows the following error,
05:18	Text string was not properly closed, expected a double quote “ ” to close the string.
05:25	Here the error is in line number 2.
05:29	I will go back to line number 2 and replace the quotes.
05:34	I will copy the program from text editor and paste it into Kturtle's Editor
05:41	Click on Run button to run the program
05:44	Enter 45 for angle value and click OK.
05:49	Program runs without errors.
05:52	This way you can find the line at which error has occured, and also correct it.
05:59	Let's now learn about runtime errors.
06:04	Run-time error occurs during the execution of a program.
06:10	It may crash the program when you run it.
06:15	Runtime errors are commonly due to wrong input from the user.
06:23	Compiler cannnot find these errors.
06:27	For example:
06:29	Trying to divide by a variable that contains no value.
06:3	Run a loop without a terminating condition or increment value.
06:43	I will clear the current program from the editor.
06:47	Type clear command and Run to clean the canvas.
06:52	I already have a program in a text editor.
06:56	This program divides two numbers.
07:00	'a' is dividend and 'r' is divisor.
07:04	I will copy the program from text editor and paste it into KTurtle's Editor.
07:11	Pause the tutorial and type the program into your KTurtle editor
07:16	Resume the tutorial after typing the program.
07:20	Let us click on Run button to run the program.
07:24	let's enter 5 for 'a' and click OK
07:29	enter 0 for 'r' and click OK
07:33	Here we get a runtime error ,
07:36	“you tried to divide by zero”
07:39	This error is in line number 4.
07:43	This error occurs as we cannot divide a number with zero.
07:49	Let us run again.
07:51	Enter 5 for a and click OK
07:54	enter 2 for 'r' and click OK
07:58	Program runs without errors.
08:01	I will clear the current program from KTurtle editor.
08:05	Type clear command and Run to clean the canvas.
08:10	Next we will learn about logical errors.
08:14	Logical error is a mistake in a program's source code that results in incorrect or unexpected behavior.
08:26	For example,
08:28	Assigning a value to the wrong variable.
08:32	Multiplying two numbers instead of adding.
08:36	I already have a program in a text editor.
08:39	I will copy the program from text editor and paste it into Kturtle's Editor
08:47	Pause the tutorial here and type the program into your KTurtle editor
08:52	Resume the tutorial after typing the program.
08:57	Now click on the Run button to run the program.
09:01	A dialog box pops-up, let's click OK.
09:05	Loop goes into an infinite loop.
09:08	We see that “while” loop prints numbers from 31 and is still printing.
09:15	This is a logical error.
09:18	In the “while” condition x is greater than 20,
09:23	but the variable x is always greater than 20
09:28	So, the loop never terminates.
09:31	I will click on Abort button to abort the process.
09:36	Let's change $x=$x+1 to $x=$x-1.
09:44	I will copy the program from text editor and paste it into KTurtle's editor.
09:51	Let's click on Run button to run the program.
09:55	A dialog box pop-up. Let us click OK.
09:59	Loop terminates after printing the values from 29 to 20.
10:05	With this we come to the end of this tutorial.
10:10	Let us summarise.
10:12	In this tutorial we have learnt, errors and types of errors such as
10:18	Use of variable that has not been declared.
10:23	Missing quotes in strings.
10:27	Runtime errors and
10:30	Logical errors
10:3	As an assignment I would like you to find errors in the given programs
10:46	Watch the video available at this URl: http://spoken-tutorial.org/What is a Spoken Tutorial
10:50	It summarises the Spoken Tutorial project
10:54	If you do not have good bandwidth, you can download and watch it
10:59	The Spoken Tutorial Project Team :
11:01	Conducts workshops using spoken tutorials
11:05	Gives certificates to those who pass an online test
11:09	For more details, please write to contact@spoken-tutorial.org
11: 17	Spoken Tutorial Project is a part of the Talk to a Teacher project
11:23	It is supported by the National Mission on Education through ICT, MHRD, Government of India
11:31	More information on this Mission is available at this link http://spoken-tutorial.org/NMEICT-Intro ]
11:37	This is Madhuri Ganpathi from IIT Bombay.Signing off
11:41	Thank you for joining

Contributors and Content Editors

Devraj, Kavita salve, PoojaMoolya, Pratik kamble, Sakinashaikh, Sandhya.np14, Sneha