KTurtle/C2/Grammar-of-TurtleScript/English

Title of the tutorial: Grammar-of-TurtleScript

Author: ITfC Bangaluru

Key words: Grammar of Turtle script, if-else condition, Comments, Commands, Numbers, Strings, Variables, Boolean values, strings and video tutorial.

Visual Cue	Narration
Slide Number 1 Title slide	Hello everybody. Welcome to this tutorial on Grammar of TurtleScript in KTurtle.
Slide Number 2 Learning Objectives	In this tutorial, we will learn about Grammar of Turtle script and 'if'-'else' condition
Slide Number 3 System Requirement	To record this tutorial I am using, Ubuntu Linux OS version. 12.04. KTurtle version. 0.8.1 beta.
Slide Number 4 Pre-requisites	We assume that you have basic working knowledge of KTurtle If not, for relevant tutorials, please visit our website. http://spoken-tutorial.org
Switch to KTurtle Application Dash home >>In the Search bar type KTurtle click on the KTurtle icon.	Let's open a new KTurtle Application. Click on Dash home. In the Search bar, type KTurtle. Click on the KTurtle icon.
Press CTRL+ALT+T >> open the Terminal >>type kTurtle >>press enter to open	We can also open KTurtle using Terminal. Press CTRL+ALT+T simultaneously to open the Terminal. Type KTurtle and press enter to open the KTurtle Application.
Slide Number 5 Turtle Script	Let's first look at TurtleScript TurtleScript is a programming language It has different types of words and symbols used for various purposes It instructs Turtle what to do
Slide Number 6 Grammar of TurtleScript	Grammar of TurtleScript in KTurtle includes- Comments Commands Numbers Strings Variables and Boolean values
Slide Number 7 Numbers	Now we will see where to store numbers Numbers can be stored in Mathematical operators Comparison operators and Variables
Zoom text	I will zoom the program text for clear view.
Switch to KTurtle window	First let's look at variables. Variables are words that start with ‘$’ sign, for example $a. In the editor they are highlighted in purple color. Using the assignment, equal to (=), a variable is given its content. Variables can contain numbers $a=100. strings $a=hello or boolean values that is true or false $a=true Variable keeps the content until program finishes execution or until it is reassigned to something else.
	For example, consider the code. $a = 2004 $b = 25 print $a + $b
	Variable 'a' is assigned a value 2004. Variable 'b' is assigned a value 25 print command, commands Turtle to write something on the canvas. print command, takes numbers and strings as input. print $a + $b commands Turtle to add two values and display them on the canvas.
Run the code	Let's Run the code in slow speed. Value 2029 is displayed on the canvas
Slide Number 8 Mathematical operators	Let us next see the Mathematical Operators. Mathematical operators include, + (Addition) - (Subtraction) * (Multiplcation) / (Division)
Clear code	I will clear the current code from editor and type clear command and RUN to clean the canvas
	I already have a program in a text editor.
	I will Explain the code now
Highlight reset	“reset” command sets Turtle to its default position
Highlight canvassize 200,200	canvassize 200,200 fixes the width and height of the canvas to 200 pixels each.
Highlight $add = 1 + 1	value 1+1 is assigned to the variable $add,
Highlight $subtract = 20 – 5	Value 20-5 is assigned to variable $subtract,
Highlight $multiply = 15 * 2	value 15 * 2 is be assigned to the variable $multiply.
Highlight $divide = 30 /30	30/30 is assigned to the variable $divide.
Highlight go 10,10	go 10,10 commands to Turtle to go 10 pixels left of canvas and 10 pixels from top of canvas
Highlight print commands	print command displays the varible on the canvas
reset canvassize 200,200 $add = 1 + 1 $subtract = 20 – 5 $multiply = 15 * 2 $divide = 30 /30 go 10,10 print $add go 50,50 print $subtract go 100,100 print $multiply go 175,175 print $divide go 0,0	I will copy the code from text editor and paste it into KTurtle editor. Pause the tutorial and type the program into KTurtle editor. Resume the tutorial after typing the program
Run code Point to the values	Let us click on Run button to run the program Command which is getting executed is highlighted on the editor. Turtle displays the values on the canvas at the specified positions.
	Let us consider a simple example for using comparison operator . Type the commands being shown on the screen.
Clear code	I will clear the current code from editor and type clear command and RUN to clean the canvas
zoom text	I will zoom the progrm text to have clear view
Switch to Kturtle Window	Let's type $answer = 10 > 3 print $answer Here 10 is compared to 3 with the ’greater than’ operator. The result of this comparison, the boolean value true is stored in the variable $answer and the value true is displayed on the canvas.
Run the code	Let's run the code now Turtle displays Boolean value true on the canvas.
Slide Number 9 Strings	Now lets see how Strings work in this application – Strings can be put in variables like numbers Strings cannot be used in mathematical or comparison operators Strings are highlighted in red color KTurtle identifies a line in double quotes as a string
clear code	I will clear the current code from editor.type clear command and Run to clean the canvas
Boolean Values	Now I will explain about Boolean values. There are only two boolean values: true and false.
	For example Let's type the code $answer = 7<5 print $answer Boolean value false is assigned to variable $answer because 7 is greater than 5
Run code	Let's Run the code now Turtle diplays Boolean value false on the canvas.
“if-else” conditon.	Let's next learn about “if-else” conditon. ‘if’ condition is executed only if the boolean value evaluates ‘true’ ‘else’ condition is executed only if the ‘if’ condition is ‘false’ .
clear code	I will clear the current code from editor.type clear command and Run to clean the canvas
	I already have a code in a text file.
Highlight the code	This code compares numbers 4 , 5 and 6 and displays the results accordingly on the canvas.
reset $x=4 if $x>5 { print $x print “is greater than five” } else { print $x print “is smaller than six” } go 0,0	I will copy the code from text editor and paste it into KTurtle editor. Pause the tutorial and type the program into KTurtle editor. Resume the tutorial after typing the program
Run code	Let's Run the code now the Turtle has compared the values 4 and 5. and has displayed the result 4 is smaller than 6 on the canvas .
	With this we come to the end of this tutorial. Let's summarize.
Slide Number 10 Summary	In this tutorial, we have learnt about Grammar of Turtle script and ‘if-else’ condition
Slide Number 11 Assignment	Now to the assignment part. Solve an equation using if - else condition Mathematical and comparision operators Display the results using “print” and “go” commands.
Slide Number 12 Assignment	To solve the assignment Choose any four random numbers Multiply two sets of random numbers Compare the results using the comparison operators Display the results Display greater result at center of the canvas You can choose any equation which you like.
Slide number 13 Acknowledgement	Watch the video available at this URL http://spoken-tutorial.org/What is a Spoken Tutorial It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it
Slide Number 14	The Spoken Tutorial Project Team : Conducts workshops using spoken tutorials Gives certificates to those who pass an online test For more details, please write to contact@spoken-tutorial.org
Slide number 15	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 this link http://spoken-tutorial.org/NMEICT-Intro ] The Script is contributed by ITfC Bangaluru. This is Madhuri Ganpathi from IIT Bombay signing off Thank you for joining.

Contributors and Content Editors

Madhurig