Ruby/C3/for-and-each-Looping-Statements/English - Revision history

Anjana at 03:35, 27 June 2013

2013-06-27T03:35:58Z

Sneha at 10:17, 22 April 2013

2013-04-22T10:17:31Z

Sneha at 09:59, 22 April 2013

2013-04-22T09:59:49Z

Nancyvarkey at 08:05, 18 April 2013

2013-04-18T08:05:48Z

Nancyvarkey at 07:40, 18 April 2013

2013-04-18T07:40:54Z

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Anjana: Created page with ''''Title of script''': '''Looping Statements''' '''Author: Anjana Nair''' '''Keywords: for, each, loop, Ruby, video tutorial''' {| style="border-spacing:0;" | style="border…'

2013-04-18T07:17:39Z

Created page with ''''Title of script''': '''Looping Statements''' '''Author: Anjana Nair''' '''Keywords: for, each, loop, Ruby, video tutorial''' {| style="border-spacing:0;" | style="border…'

New page

'''Title of script''': '''Looping Statements'''

'''Author: Anjana Nair'''

'''Keywords: for, each, loop, Ruby, video tutorial'''

{| style="border-spacing:0;"
| style="border-top:1pt solid #000000;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| <center>'''Visual Cue'''</center>
| style="border:1pt solid #000000;padding:0.097cm;"| <center>'''Narration'''</center>

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 1
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Welcome to the tutorial on '''for '''and '''each Loops''' in '''Ruby'''.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 2
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this tutorial we will learn

* Meaning of the term “loop”
* The different kinds of loops in '''Ruby'''
* Usage of “'''for'''” loop and
* Usage of “'''each'''” looping construct
*

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 3

System Requirements
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Here we are using

* '''Ubuntu''' version 12.04
* '''Ruby''' 1.9.3

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 4

Pre-requisites
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| To follow this tutorial, you must have '''Internet''' Connection.

You must also have knowledge of '''Linux''' commands, '''Terminal''' and '''Text-editor.'''

If not, for relevant tutorials, please visit our website.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now let me explain what is referred to as a “'''loop'''” in '''Ruby'''.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5

What is a loop?
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| A '''loop '''is a command or set of commands that are executed a fixed number of times.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 6

Looping statements
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| '''Ruby''' has the following main looping statements.

* '''for '''
* '''each'''
* '''while'''
* '''until '''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this tutorial we will learn how to use the '''for''' and '''each''' looping constructs.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to gedit
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Click on “'''dash-home'''” and type '''gedit''' to invoke the editor.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to terminal
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Similarly, click on “'''dash-home'''” and select '''Terminal''' to open the '''terminal'''.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Type mkdir ttt and press Enter
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In the '''terminal,''' type “'''mkdir ttt'''”.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Type cd ttt and press Enter
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Then “'''cd'''” into that directory.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Type mkdir ruby-tutorial and press Enter
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Then type “'''mkdir ruby-tutorial'''”,

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Type cd ruby-tutorial and press Enter
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| And then “'''cd''' '''ruby-tutorial'''”.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Type mkdir looping-statements and press Enter
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Then type “'''mkdir looping-statements'''”

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Type cd looping-statements and press Enter
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| And then “'''cd looping-statements'''”

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now we have created the requisite folders.

Let's move ahead.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7

“for” loop
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The syntax of the “'''for'''” loop in '''Ruby''' is as follows:

'''for “variable” in “a collection of objects”'''

'''ruby code'''

'''end'''

Let us try to understand it with an example.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to gedit where you have already opened the file “for-loop.rb” with the '''for loop '''code typed inside.
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Create a new file in '''gedit''' as shown in the basic level '''Ruby '''tutorials.

And name it “'''for-loop.rb'''”

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| I already have a working example of the “'''for”''' loop.

You can type the code as we go through this example.

Pause the tutorial while you do this.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “for”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| I have declared a “'''for”''' loop in this example.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight (1..20)
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| We have a set of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “for i in (1..20)”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| We declare a variable called “'''i'''” within the “'''for”''' loop.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The variable '''“i” '''gets initialised to the first element in the set of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The “'''for'''” loop declaration causes the code to iterate over each element in the set 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “puts”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The “'''puts'''” method declared within the “'''for'''” loop is responsible for generating the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to the terminal and type

ruby for-loop.rb

Point to the output
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now open the '''terminal''' and type

“'''ruby for-loop.rb'''”

and see the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Analyzing the output
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The output will be an '''array''' of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this example, we declared a “'''for'''” loop for an inclusive range.

It included all numbers from 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Next we shall look at implementing the “'''for'''” loop for a non-inclusive range.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch back to the same file.
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let's get back to the same file we were looking at.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Continue to type the next part of the code.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “for i in (1...20)”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Non-inclusive means it will not include the last element in the collection of objects.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Here a “'''for'''” loop is implemented for a non-inclusive range of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| You will notice shortly that the number 20 will not be printed in the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight the 3 dots only
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The last digit does not get included when you have 3 dots between numbers.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to the terminal and type

ruby for-loop.rb

Point to the output
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| '''No'''w open the terminal and type “'''ruby for-loop.rb'''”

and see the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Analyzing the output
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The output will still be an array of numbers but will not include the number 20.

<nowiki><Pause></nowiki>

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now, you should be capable enough to write your own “'''for'''” loop.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 8

“each” loop
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The syntax of the “'''each'''” loop in '''Ruby '''is as follows:

'''“a collection of objects”.each do |item|'''

'''ruby code'''

'''end'''

Let us try to understand it with an example.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to gedit where you have already opened the file “each-loop.rb” with the '''each loop '''code typed inside.
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Create a new file in '''gedit''' as shown in the basic level '''Ruby''' tutorials.

And name it “'''each-loop.rb'''”

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| I already have a working example of the “'''each”''' loop.

You can type the code as we go through this example.

Pause the tutorial while you do this.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “for”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| I have declared an “'''each'''” loop in this example.

We have a set of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “for i in (1..20)”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| We declare a variable called “'''i'''” within the “'''each'''” loop.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The “'''i'''” variable gets initialised to the first element in the set of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The '''“each”''' loop declaration causes the code to iterate over each element in the set 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “puts”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The “'''puts'''” method declared within the “'''each'''” loop is responsible for generating the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to the terminal and type “'''ruby each-loop.rb'''”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now open the '''terminal''' and type “'''ruby each-loop.rb'''”

and see the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Analyzing the output
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The output will be an array of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In the above example we declared an “'''each'''” loop for an inclusive range.

It included all numbers from 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Next we shall look at implementing the “'''each'''” loop for a non-inclusive range.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch back to gedit
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let's get back to the same file we were looking at.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Continue to type the next part of the code.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “for i in (1...20)”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Non-inclusive means it will not include the last element in the collection of objects.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Here a “'''each'''” loop is implemented for a non-inclusive range of numbers 1 to 20.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Continue the highlight
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| You will notice shortly that the number 20 will not be printed in the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight the 3 dots only
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The last digit does not get included when you have 3 dots between numbers.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Switch to the terminal and type

ruby each-loop.rb

Point to the output
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| '''No'''w open the terminal and type “'''ruby for-loop.rb'''”

and see the output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now you should be capable enough to write your own “'''each'''” loop.

<nowiki><Pause></nowiki>

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 9
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| How would we determine which looping contruct to choose?

Let us try to recall the “'''for'''” loop construct.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Open “for-loop.rb”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In the first example, we iterated over a set of numbers 1 to 20 using “'''for'''”.

Execute “ruby for-loop.rb” in your terminal and see the output.

Now look at the code in '''gedit.'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight “for number in (1..20)”
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| When you invoke the “'''for'''” loop, Ruby is actually calling the “'''each'''” method behind the scenes.

And calling “'''each'''” or '''“for”''' will generate the same output.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Since the call to “'''for'''” in turn calls “each”, it is preferable to use the “'''each'''” loop instead.

<nowiki><Pause></nowiki>

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 10
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| <nowiki><<Pause>></nowiki>

This brings us to the end of this Spoken Tutorial.

Let's summarize.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 11

Summary
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this tutorial we have learnt

* Usage of “'''for'''” loop
* Usage of “'''each'''” construct
* Reasoning behind using “'''each'''” instead of “'''for'''”
* Examples of using the above looping constructs

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 12

Assignment
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| As as assignment

Write a ruby program using

* the appropriate loop construct
* to create an output of even numbers
* from a set of numbers, say 1 to 20

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 13

About the Spoken Tutorial Project
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Watch the video available at the following link.

It summarises the Spoken Tutorial project.

If you do not have good bandwidth, you can download and watch it.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 14
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| 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 at spoken hyphen tutorial dot org

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 15

Acknowledgements
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| 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:

spoken hyphen tutorial dot org slash NMEICT hyphen Intro.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Slide 16

About the contributor

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| * This tutorial has been contributed by Ruby Software Pvt. Ltd
* http://www.ruby-software.com
* Thank you

|}

@@ Line 418: / Line 418: @@
 |-
-| Slide 16
+| style="background-color:#ffffff;border-top:0.25pt solid #000000;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:0.25pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.095cm;padding-right:0.095cm;"| Previous slide
 |}

@@ Line 70: / Line 70: @@
 |-
 | Type mkdir ttt and press Enter
-| Before we begin, please create the following folders in your home directory,ttt, ruby-tutorial, looping-statements.  please create the sub- folder as mentioned here Now we have created the requisite folders. Let see them ahead
+| Before we begin, please create the following folders in your home directory,ttt, ruby-tutorial, looping-statements.  please create the sub- folder as mentioned here.
-−
@@ Line 122: / Line 121: @@
 |-
 | Continue the highlight
-| The variable '''“i” '''gets initialised to the first element in the set of numbers 1 to 20.
+| The variable '''“i” '''gets initialized to the first element in the set of numbers 1 to 20.
 |-
@@ Line 247: / Line 246: @@
 |-
 | Continue the highlight
-| The “'''i'''” variable gets initialised to the first element in the set of numbers 1 to 20.
+| The “'''i'''” variable gets initialized to the first element in the set of numbers 1 to 20.
 |-
@@ Line 323: / Line 322: @@
 |-
 | Slide 9
-| How would we determine which looping contruct to choose?
+| How would we determine which looping construct to choose?
 Let us try to recall the “'''for'''” loop construct.
@@ Line 332: / Line 331: @@
-Execute “ruby for-loop.rb” in your terminal and see the output.
+Execute “ruby for-loop.rb” in you have to anyways and see the output.

@@ Line 66: / Line 66: @@
 | In this tutorial we will learn how to use the '''for''' and '''each''' looping constructs.
 |-
 | Type mkdir ttt and press Enter
-| In the '''terminal,''' type “'''mkdir ttt'''”.
+| Before we begin, please create the following folders in your home directory,ttt, ruby-tutorial, looping-statements.  please create the sub- folder as mentioned here Now we have created the requisite folders. Let see them ahead
-−
-|-
-| Type cd ttt and press Enter
-| Then “'''cd'''” into that directory.
-−
-|-
-| Type mkdir ruby-tutorial and press Enter
-| Then type “'''mkdir ruby-tutorial'''”,
-−
-|-
-| Type cd ruby-tutorial and press Enter
-| And then “'''cd''' '''ruby-tutorial'''”.
-−
-|-
-| Type mkdir looping-statements and press Enter
-| Then type “'''mkdir looping-statements'''”
-−
-|-
-| Type cd looping-statements and press Enter
-| And then “'''cd looping-statements'''”
 |-
+|
@@ Line 131: / Line 107: @@
 You can type the code as we go through this example.
 |-
@@ Line 185: / Line 160: @@
 | Next we shall look at implementing the “'''for'''” loop for a non-inclusive range.
 |-
@@ Line 216: / Line 188: @@
 Point to the output
-| '''No'''w open the terminal and type “'''ruby for-loop.rb'''”
+| '''Now open the terminal and type “'''ruby for-loop.rb'''”
@@ Line 261: / Line 233: @@
-Pause the tutorial while you do this.
 |-
@@ Line 338: / Line 310: @@
 Point to the output
-| '''No'''w open the terminal and type “'''ruby for-loop.rb'''”
+| '''Now open the terminal and type “'''ruby each-loop.rb'''”
@@ Line 357: / Line 329: @@
 |-
 | Open “for-loop.rb”
-| In the first example, we iterated over a set of numbers 1 to 20 using “'''for'''”.
+| In the first example, we iterated over a set of numbers from 1 to 20 using “'''for'''”.

@@ Line 401: / Line 401: @@
 Assignment
-| As as assignment
+| As an assignment
 Write a ruby program using