Difference between revisions of "Ruby/C2/Hello-Ruby/English-timed"

| Welcome to the '''Spoken Tutorial''' on  '''Hello Ruby!'''.

| In this tutorial, we will learn  

| Features, '''RubyGems''' & Help on Ruby

|  Installation, Running '''Ruby''' code

|  Commenting,  Difference between '''puts''' and '''print'''.

| Here, we are using: '''Ubuntu Linux '''version '''12.04''', '''Ruby''' 1.9.3

|  To follow this tutorial, you must be connected to internet.  

| You must have the knowledge of using '''Terminal '''and '''Text editor '''in '''Linux'''.  

|  Now, I will explain you what is '''Ruby'''.

|  Now, let us see some features of '''Ruby'''.

|  Variables in '''Ruby''' have no datatype such as in '''Smalltalk, BASIC''' or '''Python'''.

|  '''Ruby''' is a free format language.

|  '''Ruby''' is used for developing Internet and '''Intra-net''' '''application'''s.

| One of the most important features of '''Ruby''' is '''RubyGems'''.

| '''RubyGems''' is a '''package manager''' for  '''Ruby''' programming language.

| It provides a standard format for distributing''' Ruby''' programs and '''libraries'''.

| For more information on '''RubyGems''', visit the following link.

|  To get more help on Ruby, you can visit the links shown.

| You can install Ruby using '''Ubuntu Software Centre'''.

| For more information on '''Ubuntu Software Centre''', please refer to the '''Ubuntu Linux Tutorials''' on this website.

|  Other methods for installing Ruby are as shown in this slide.

| '''Ruby code '''can be executed in 3 ways-

| '''Command line ''', '''Interactive Ruby''' and

| As a '''file'''. We will go through each method of execution.

|  First, let us see how to execute the  '''Hello World''' code from  '''command line'''.

| Open a '''terminal''' by pressing the '''Ctrl, Alt''' and '''T '''keys simultaneously.  

| A '''terminal window''' appears on your screen.

|  Type the command: '''ruby''' ''space'' ''hyphen'' '''e''' ''space'' within single quotes '''puts''' ''space'' then within double quotes '''Hello World''' and

| press '''Enter.'''

| We get the output as "HelloWorld".

| '''puts '''command is used to print the output on the '''terminal.'''

|  The hyphen 'e' '''flag''' allows only a single line of a code to be executed.

| Multiple hyphen 'e' flags can be used to execute multiple line commands.  

| Let's try this out.

|  Now, press the up-arrow key to get the previous command and  

| type: ''space'' ''hyphen'' '''e''' ''space '' within single quotes '''puts ''' ''space'' '''1+2 '''and

| press''' Enter.'''

|  We get the output as "Hello World" and''' 3.'''

| Let's switch back to our '''slide'''.

| 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 the return values.

| For older version of Ruby, install the '''irb''' separately.

| Now, let us execute our Ruby code through 'irb'. Go to the '''terminal'''.

| Type "irb"  and press '''Enter'''  

| to launch the '''Interactive Ruby'''.

| Type: '''puts ''' ''space'' within double quotes '''Hello World''' and press '''Enter.'''

|We get the output as '''Hello World'''

| and we get the return value as '''nil.'''

|  To exit from '''irb ''', type '''exit''' and press '''Enter.'''

|  You can also run the '''Ruby program''' from a file.

|  I am using '''gedit '''text editor. Let me switch to  '''gedit''' text editor.

|  Now, type: '''puts''' ''space'' within double quotes''' Hello World '''.

| Let's learn how to add '''multiple line''' or '''block comments'''.

|  Before the '''puts '''command,

| type: ''equal to'' '''begin '''and press '''Enter'''.

| ''equal to'' '''begin '''is used to start the comment.

| I will type: "My first Ruby program"

| and press '''Enter'''.

| Then type: "This code will print helloworld" and press '''Enter'''.

|  Now, type: ''equal to'' '''end'''.

| ''equal to'' '''end '''is used to end the '''multiple line comments'''.

|  '''Comment'''s are useful to understand the flow of program.

| It is useful for '''documentation'''.

|  The '''Save As '''dialog-box appears on your screen.  

|  On '''Desktop,''' I will create a folder named "rubyprogram".  

| I will type "hello.rb".

|  '''dot rb''' extension is given to a '''Ruby '''file.

|  Then click on the '''Save '''button to save the file.  So, the file is saved now.  

| Let's clear the terminal first.

| Remember that we are in the '''home '''directory. We need to go to the sub-directory '''rubyprogram'''.

| To do so, type: '''cd''' ''space'' '''Desktop/rubyprogram''' and press '''Enter.'''  

|  Let's execute the file. Type: '''ruby''' ''space'' '''hello dot rb''' and press '''Enter'''.

| We get the output as "HelloWorld".

|  Now, let me demonstrate the difference between '''puts''' and '''print '''statements.

| We will try this out using "irb".

|  Before that, we need to go back to our '''home''' directory. To do so, type "cd" and press '''Enter'''.

|Now, type "irb" and press '''Enter''' to launch the '''Interactive Ruby.'''

|  Type: '''puts''' ''space'' within double quotes '''Hello '''comma within double quotes '''World '''.

| Here,''' comma '''is used to join the two '''puts''' commands together.

| Now, press '''Enter.'''

|  We get the output '''Hello,  World,''' but on the separate lines.

|  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.'''

| The keyword''' print '''outputs only what we have provided.

| This brings us to the end of this Spoken Tutorial. Let us switch back to our slide.

| In this tutorial, we have learnt:

| About '''Ruby''', Installation

| Execution of '''Ruby '''code  

| Difference between '''puts''' and '''print'''.

| 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'''.

| It summarizes the Spoken Tutorial project.

| 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

|  '''Spoken Tutorial''' project is a part of the '''Talk to a Teacher''' project.

| More information on this mission is available at the below link.

| This is Afrin Pinjari from '''IIT Bombay''', signing off.