KTurtle/C2/Grammar-of-TurtleScript/English-timed
From Script | Spoken-Tutorial
| 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,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. |
