Ruby/C2/Hello-Ruby/English
Title of script: Hello Ruby!
Author:Afrin Pinjari
Keywords: Ruby,video tutorial, helloworld, puts, print
Visual Cue | Narration |
Slide 1 | Welcome to the Spoken Tutorial on Hello Ruby! |
Slide 2
Learning Objectives |
In this tutorial we will learn
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Slide 3
System Requirements |
Here we are using
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Slide 4
Pre-requisites |
To follow this tutorial you must be connected to the internet.
You must have knowledge of using Terminal and Text editor in Linux. |
Slide 5
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Now I will explain what is Ruby.
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Slide 6
Features |
Now let us see some features of Ruby.
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Slide 7
RubyGems |
One of the most important feature of Ruby is RubyGems.
RubyGems is a package manager for the Ruby programming language. It provides a standard format for distributing Ruby programs and libraries. You can create and publish your own gems. For more information on RubyGems visit the following link. |
Slide 8
Help on Ruby |
To get more help on Ruby you can visit the links shown. |
Slide 9
Installation |
You can install Ruby using the Ubuntu Software Centre.
For more information on Ubuntu Software Centre, please refer to the Ubuntu Linux Tutorials on this website. |
Slide 10 | Other methods for installing Ruby are as shown in this slide. |
Slide 11
Running Ruby |
Ruby code can be executed in 3 ways
We will go through each method of execution. |
First let us see how to execute 'Hello World' code from the command line. | |
Switch to Terminal
Press Ctrl+Alt+t |
Open a terminal by pressing the Ctrl, Alt and T keys simultaneously.
A terminal window appears on your screen. |
Type
ruby -e 'puts ”Hello World”'<<press Enter |
Type the command
ruby space hyphen e space within single quotes puts space then within double quotes Hello World and Press Enter. |
Highlight Hello world | We get the output as Hello World. |
Highlight puts | puts command is used to print the output on the terminal. |
Highlight -e | The hyphen e flag allows only a single line of code to be executed.
Multiple hyphen e flags can be used to execute multiple line commands. Lets try this out |
Press Up Arrow key | Now press the up Arrow key to get the previous command and |
Type
ruby -e 'puts “Hello World”' -e 'puts 1+2'<< Press Enter |
Type
space hypen e space within single quotes puts space 1+2 and Press Enter. |
Highlight
Hello World and 3 |
We get the output as Hello World and 3.
Let's switch back to our slide |
Slide 11
Interactive Ruby |
We will now learn about Interactive Ruby.
Interactive Ruby allows the execution of Ruby commands with immediate response. You can run Ruby statements and examine the output and return values. For older version of Ruby, install irb separately. |
Switch to the Terminal
Type irb<< press Enter |
Now let us execute our Ruby code through irb.
Go to the terminal. Type irb and press Enter to launch Interactive Ruby. |
Type puts ”Hello World” <<Press Enter | Type puts space within double quotes Hello World and press Enter. |
Highlight Hello World and nil | We get the output as Hello World.
And we get the return value as nil. |
Type exit <<Press Enter | To exit from irb type exit and press Enter. |
You can also run Ruby program from a file.
You can use any text editor of your choice to write the code. | |
Switch to text editor | I am using gedit text editor.
Let me switch to gedit text editor. |
Type puts ”Hello World ” | Now, type puts space within double quotes Hello World |
Lets learn how to add multiple line or block comments. | |
Type =begin <<press Enter | Before the puts command
Type, equal to begin and press Enter |
Highlight =begin | Equal to begin is used to start the comment. |
Type
My first Ruby program This code will print Hello world Press Enter |
Type the comments that you wish to add.
I will type My first Ruby program. Press enter This code will print Hello world. Press Enter |
Type
=end |
Now type
equal to end |
Highlight =end | equal to end is used to end multiple line comments. |
Comments are useful to understand the flow of program.
It is useful for documentation. | |
Click on the Save button | Now, let us save the file by clicking on the Save button.
It is a good practice to save the file frequently. |
In the Save As dialog box >> Browse the location to save the file | The Save As dialog box appears on your screen.
Browse the location where you want to save the file. |
Create a folder named rubyprogram on the Desktop. | On Desktop, I will create a folder named rubyprogram.
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In Name text-box >> type
hello.rb |
In the Name text-box, type the name that you wish to add.
I will type hello.rb |
Point to Dot rb extension | Dot rb extension is given to a Ruby file |
Click on Save button | Then click on Save button to save the file.
So the file is saved now. |
Switch to the terminal. | To execute the code, go to the terminal.
Lets clear the terminal first. |
Make sure that you are in the directory where your Ruby file is present. | |
Remember that we are in the home directory. We need to go to the subdirectory rubyprogram. | |
Type cd Desktop/rubyprogram<< Press Enter | To do so, type cd space Desktop/rubyprogram and press Enter. |
Type ruby hello.rb <<Press Enter | Let's execute the file
Type ruby space hello dot rb and press Enter |
Highlight HelloWorld | We get the output HelloWorld. |
Now let me demonstrate the difference between puts and print statement.
We will try this out using irb | |
Type
cd <<press Enter |
Before that we need to go back to the home directory
To do so type cd and press Enter |
In the terminal
Type irb<< press Enter |
Now type
irb and Press Enter to launch the Interactive Ruby. |
Type puts “Hello”,”World” | Type
puts space within double quotes Hello comma within double quotes World |
Highlight or point to comma
Press Enter |
Here comma is used to join the two puts command together.
Now press Enter. |
Highlight Hello World | We get the output Hello World, but on separate lines. |
Type print “Hello”,”World”
<<Press Enter |
Now let's try the same thing with print.
Press up arrow key to get the previous command Replace puts with print and Press Enter. |
Highlight HelloWorld | We get the output as Hello World but on the same line. |
The keyword puts adds a newline to the end of the output. The keyword print does not. | |
The keyword print outputs only what we have provided. | |
<<Pause>>
This brings us to the end of this Spoken Tutorial. | |
Slide 11
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In this tutorial we have learnt
=begin ...... =end
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Slide 13
Assignment |
As an assignment
Write a program to print your name and age We used multiple line comments in this tutorial Try to give single line comment Hint: #............... |
Slide 14
About the Spoken Tutorial Project |
Watch the video available at the following link.
If you do not have good bandwidth, you can download and watch it. |
Slide 15 | The Spoken Tutorial Project Team :
Gives certificates to those who pass an online test For more details, please write to contact@spoken-tutorial.org |
Slide 16
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 below link: spoken-tutorial.org/NMEICT-Intro. |
NO SLIDE
On the previous slide itself. |
This is Afrin Pinjari from IIT Bombay, signing off.
Thank you for watching. |