KTurtle/C2/Grammar-of-TurtleScript/English-timed

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Time Narration
00:01 Hello everybody.Welcome to this tutorial on Grammar of TurtleScript in KTurtle.
00:08 In this tutorial, we will learn about
00:11 grammar of Turtle script and 'if'-'else' condition.
00:16 To record this tutorial, I am using:

Ubuntu Linux OS version 12.04 KTurtle version 0.8.1 beta.

00:29 We assume that you have basic working knowledge of KTurtle.
00:35 If not, for relevant tutorials, please visit our website: http://spoken-tutorial.org
00:40 Let's open a new KTurtle Application.
00:43 Click on Dash home.
00:45 In the Search bar, type: "kturtle".
00:49 Click on the KTurtle icon.
00:52 We can also open KTurtle using Terminal.
00:56 Press Ctrl+Alt+T keys simultaneously to open the Terminal.
01:01 Type kturtle and press Enter to open the 'KTurtle' Application.
01:08 Let's first look at TurtleScript.
01:11 TurtleScript is a programming language.
01:15 It has different types of words and symbols used for various purposes.
01:21 It instructs Turtle what to do.
01:25 Grammar of TurtleScript in KTurtle includes-
01:30 Comments, Commands
01:32 Numbers, Strings
01:34 Variables and
01:36 Boolean values.
01:38 Now, we will see where to store numbers.
01:42 Numbers can be stored in:
01:44 Mathematical operators
01:46 Comparison operators and
01:49 Variables
01:50 I will zoom the program text for clear view.
01:54 First let's look at variables.
01:57 Variables are words that start with ‘$’ sign, for example $a.
02:04 Variables are highlighted in purple color.
02:09 Using the assignment equal to (=), a variable is given its contents.
02:14 Variables can contain- * numbers $a=100.
02:20 strings $a=hello or
02:25 boolean values that is true or false $a=true.
02:32 Variable keeps the contents until program finishes execution or until it is reassigned to something else.
02:41 For example, consider the code.
02:44 Let us type:$a = 2004
02:50 $b = 25
02:55 print $a + $b
03:01 Variable 'a' is assigned a value 2004.
03:06 Variable 'b' is assigned a value 25.
03:10 print command, commands Turtle to write something on the canvas.
03:15 print command takes numbers and strings as input.
03:19 print $a + $b commands Turtle to add two values and display them on the canvas.
03:29 Let's Run the code in slow speed.
03:34 Value 2029 is displayed on the canvas.
03.40 Let us next see the mathematical operators.
03:44 Mathematical operators include -

'+' (Addition)

'-' (Subtraction)

'*' (Multiplication) and

'/' (Division)

03:53 I will clear the current code from the editor and type "clear" command and Run to clean the canvas.
04:01 I already have a program in a text-editor.
04:05 I will explain the code now.
04:08 “reset” command sets Turtle to its default position.
04:12 canvassize 200,200 fixes the width and height of the canvas to 200 pixels each.
04:22 Value 1+1 is assigned to the variable $add.
04:26 Value 20-5 is assigned to the variable $subtract.
04:31 Value 15 * 2 is assigned to the variable $multiply.
04:36 30/30 is assigned to the variable $divide.
04:40 go 10,10 commands Turtle to go 10 pixels left of canvas and 10 pixels from top of canvas.
04:52 print command displays the variable on the canvas.
04:56 I will copy the code from text-editor and paste it into KTurtle editor.
05:03 Pause the tutorial here and type the program into your KTurtle editor.
05:08 Resume the tutorial after typing the program.
05:13 Let us click on Run button to run the program.
05:17 Command which is getting executed is highlighted on the editor.
05:22 Turtle displays the values on the canvas at the specified positions.
05:34 Let us consider a simple example for using comparison operator .
05:41 I will clear the current code from the editor. Type "clear" command and Run to clean the canvas.
05:49 I will zoom the program text to have a clear view.
05:53 Let's type:
05:55 $answer = 10 > 3
06:03 print $answer
06:09 Here, 10 is compared to 3 with the greater than operator.
06:14 The result of this comparison, the boolean value 'true', is stored in the
06:19 variable $answer and the value 'true' is displayed on the canvas.
06:27 Let's run the code now.
06:29 Turtle displays Boolean value 'true' on the canvas.
06:34 Now, let's see how Strings work in this application-
06:39 Strings can be put in variables like numbers.
06:43 Strings cannot be used in mathematical or comparison operators.
06:49 Strings are highlighted in red color.
06:53 'KTurtle' identifies a line in double quotes as a string.
07:00 I will clear the current code from editor. Type "clear" command and Run to clean the canvas.
07:08 Now, I will explain about Boolean values.
07:11 There are only two boolean values: "true" and "false".
07:16 For example, let's type the code:
07:20 $answer = 7<5
07:28 print $answer.
07:34 The Boolean value 'false' is assigned to the variable $answer because 7 is greater than 5.
07:43 Let's Run the code now.
07:47 Turtle displays Boolean value "false" on the canvas.
07:51 Let's next learn about “if-else” conditon.
07:56 ‘if’ condition is executed only if the boolean value evaluates ‘true’.
08:03 ‘else’ condition is executed only if the ‘if’ condition is ‘false’.
08:09 I will clear the current code from editor. Type "clear" command and Run to clean the canvas.
08:17 I already have a code in a text file.
08:21 This code compares numbers 4 , 5 and 6 and displays the results accordingly on the canvas.
08:30 I will copy the code from text-editor and paste it into KTurtle editor.
08:36 Pause the tutorial here and type the program into your KTurtle editor.
08:42 Resume the tutorial after typing the program.
08:46 Let's run the code now.
08:49 The Turtle has compared the values 4 and 5
08:53 and has displayed the result: "4 is smaller than 6" on the canvas.
09:00 With this we come to the end of this tutorial.
09:05 Let's summarize.
09:07 In this tutorial, we have learnt about:
09:11 Grammar of Turtle script and
09:14 ‘if-else’ condition.
09:17 Now, to the assignment part.
09:19 Solve an equation using:
09:22 if - else condition,
09:24 Mathematical and comparison operators.
09:27 Display the results using “print” and “go” commands.
09:33 To solve the assignment-
09:35 choose any four random numbers,
09:38 multiply two sets of random numbers,
09:42 compare the results using the comparison operators,
09:46 display both the results,
09:49 display greater result at the center of the canvas.
09:54 You can choose any equation which you like.
09:59 Watch the video available at this URL: http://spoken-tutorial.org/What_is_a_Spoken-Tutorial
10:03 It summarizes the Spoken Tutorial project.
10:06 If you do not have good bandwidth, you can download and watch it.
10:12 The Spoken Tutorial project team :
10:14 Conducts workshops using spoken tutorials.
10:18 Gives certificates to those who pass an online test.
10:22 For more details, please write to: contact@spoken-tutorial.org
10:30 Spoken Tutorial project is a part of the Talk to a Teacher project.
10:35 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
10:43 More information on this mission is available at this link: http://spoken-tutorial.org/NMEICT-Intro
10:48 The Script is contributed by ITfC, Bangaluru.
10:52 This is Madhuri Ganpathi from IIT Bombay, signing off. Thank you for joining.

Contributors and Content Editors

Devraj, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha