Antarade: Created page with "'''Title of script: Basics of single Dimensional Array in Awk''' '''Author: Antara Roy Choudhury''' '''Keywords: Array, assigning array element, referring array element, che..."

2018-02-15T14:45:05Z

Created page with "'''Title of script: Basics of single Dimensional Array in Awk''' '''Author: Antara Roy Choudhury''' '''Keywords: Array, assigning array element, referring array element, che..."

New page

'''Title of script: Basics of single Dimensional Array in Awk'''

'''Author: Antara Roy Choudhury'''

'''Keywords: Array, assigning array element, referring array element, checking for presence of an element'''

{| style="border-spacing:0;"
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| <center>'''Visual Cue'''</center>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| <center>'''Narration'''</center>

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 1
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Welcome to this spoken tutorial on '''Basics of single dimensional array''' in '''awk'''.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 2
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| In this tutorial we will learn about-

* '''Arrays''' in '''awk'''
* Assigning '''array elements'''
* How it is different from '''arrays''' in other programming languages and
* Refer the '''elements '''of an '''array '''

We will do this through some examples.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 3

System requirement
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| To record this tutorial, I am using

* '''Ubuntu Linux 16.04 Operating System '''and''' '''
* '''gedit text editor 3.20.1'''

You can use any text editor of your choice.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 4

pre-requisite
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| To practice this tutorial, you should have gone through previous '''awk''' tutorials on our website.

You should have some basic knowledge of any programming language like '''C''' or '''C++'''.

If not, then please go through the corresponding tutorials on our website.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 5: Code Files
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| The files used in this tutorial are available in the '''Code Files''' link on this tutorial page.

Please download and extract them.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 5
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| What is an '''array''' in '''awk'''?

* '''awk''' supports '''arrays''' for storing related '''elements'''.
* '''Elements '''can be a '''number '''or a '''string'''.
* '''Arrays '''in '''awk '''are '''''associative'''''.
* This means that each '''array element '''is an '''index-value pair.'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 6
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| It looks very similar to '''arrays '''in any other programming language.

But there are some important differences.

* First, we do not need to '''declare '''an '''array''' before using it.
* Also there is no need to specify how many '''elements''' the '''array '''will contain.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 7
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| * In programming languages, '''array index '''is generally a positive integer.
* Usually the '''index''' starts from 0, then 1, then 2 and so on.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 8
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| * But in '''awk''', the '''index '''can be anything – any '''number '''or a '''string.'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 9:

<nowiki>array-name[index] = value</nowiki>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| This is the syntax of assigning an '''array element '''in '''awk.'''

'''Array name''' can be any valid variable name.

Here the '''index''' can be an '''integer''' or a '''string.'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Slide 10
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| '''Strings''' have to be written inside double quotes, whether it is a '''index '''name or a '''value'''.

Let’s understand this with an example.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Show '''array_intro.awk '''in''' gedit'''
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| I have already written the code and saved it as '''array_intro.awk'''

This file is available in the '''Code Files''' link below the player.

Please download and use it.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| <nowiki>Highlight day[1] = </nowiki>“Sunday”
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Here I have taken weekdays as an example and written it inside the '''BEGIN section'''.

Here, the name of the '''array '''is '''day'''.

I have set the '''index '''as 1 and the value as '''Sunday'''.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| <nowiki>Highlight day[“first”] = “Sunday”</nowiki>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| In the '''array element''', I have used a '''string '''as the '''index.'''

So for '''index first, '''the value is '''Sunday'''.

The entire '''array''' is constructed likewise.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight the portion

'''<nowiki>day[4]="wednesday"</nowiki>'''

<nowiki>day["fourth"]="wednesday"</nowiki>

'''<nowiki>day[3]="tuesday"</nowiki>'''

<nowiki>day["third"]="tuesday"</nowiki>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Notice here, the '''array elements''' are not in a sequence.

I have declared '''day four '''before '''day three'''.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display slide 11
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| * In '''awk arrays, index '''need not to be in a sequential manner.
* Advantage of '''associative array''' is that new pairs can be added at any time.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to gedit and Type:

<nowiki>day[6]="Friday" </nowiki>

<nowiki>day["sixth"]="Friday"</nowiki>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Let me add day 6 in the '''array'''.

Place the cursor at the end of the last line and press '''Enter'''.

Then type the following

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Press Ctrl+S
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save the file.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display slide 12
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We have declared the '''array'''.

But how should we refer to the '''array element'''?

Write the '''arrayname '''and the''' index '''within''' square brackets '''to refer an '''element '''at a particular '''index.'''

Let us try this.''' '''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to gedit

Type:

<nowiki>print day[6]</nowiki>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to the code once again.

Place the cursor in front of the closing '''curly brace'''.

Press '''Enter''' and type '''print '''''space '''''day '''''within square brackets '''''6'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Press Ctrl+S
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save the code.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"|
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Open the '''terminal''' by pressing '''Ctrl''', '''Alt''' and '''T''' keys

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| <nowiki>cd /<saved folder></nowiki>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Go to the folder in which you downloaded and extracted the '''Code Files''' using '''cd command'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Type:

awk -f array_intro.awk

<nowiki>[Enter]</nowiki>
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Now type

'''awk space hyphen small f space array_intro.awk '''

Press '''Enter'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Show the output
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| See, we get '''Friday''' as the output.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display slide 12
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Next we will check whether any '''element''' exists in an '''array''' at a certain '''index'''.

For this, we have to use the '''in operator'''.

Let me explain this with an example.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to gedit

Type:

<nowiki>if (2 in day) [</nowiki>'''''Enter]'''''

print "Index 2 is present."

'''''<nowiki>[Enter]</nowiki>'''''

<nowiki>if (7 in day) [</nowiki>'''''Enter]'''''

print "Index7 is present."
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to the code in the editor window.

Place the cursor at the end of the '''print statement''' and press''' Enter.'''

Then type as shown.

Save the code.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight Both the if statements

Highlight if (2 in day)

Highlight print "Index 2 is present."

Highlight

if (7 in day)

print "Index7 is present."

| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Now I have added two '''if conditions.'''

The first '''if condition '''checks whether the '''index two '''is present in '''day.'''

If yes, then the corresponding '''print statement '''will get executed.

Then the second '''condition '''checks whether the '''index seven '''is present in '''day.'''

It will execute the '''print statement '''if it is '''true'''.

As we can see, '''index two''' is in the '''array''' and '''seven''' is not.

Let’s execute this file to verify the output.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to terminal
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to the '''terminal'''.

Press the '''Up arrow key''' to get back the previously executed command.

Press '''Enter '''to execute.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight '''Index 2 is present.''' in the output
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We get the output as expected.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| In gedit, type

<nowiki>if (day[7] != "") </nowiki>

print "Index 7 is not null"

if (7 in day)

print "Index 7 is present after null comparison."
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We will now make some more changes to the code.

Update the code as shown here.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight '''<nowiki>if (day[7] != "")</nowiki>'''
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Below the '''7''' in''' day condition''', I have added one more '''condition'''.

This will check whether the value of''' index seven''' is null or not.

If '''true''', it will print '''Index 7 is not null'''

We already know that we don’t have any '''index '''with '''7''', so it will not print anything.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight '''"Index 7 is present after null comparison."'''
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Next, we’ll change the '''print statement '''of the '''condition 7 '''in '''day.'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save the code

| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Save the code.

Let’s see what happens when we execute the code.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to terminal

press Up arrow key

Press Enter
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to '''terminal.'''

Press the up arrow key to get the previous command.

Press '''Enter''' to execute.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight '''"Index 7 is present after null comparison."'''
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| We got an unexpected output.

The statement '''"Index 7 is present after null comparison."'''

is printed.

How is it possible?

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Switch to gedit window

Highlight

'''<nowiki>if (day[7] != "") </nowiki>'''
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| When we write, '''<nowiki>day[7] </nowiki>'''''not equal to''''' null''', we are trying to access the '''element''' at '''index 7.'''

This access itself will first create an element at '''index 7 '''and initialize it with the value '''null'''.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Highlight

'''if (7 in day)'''
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Next, we are trying to check if any '''element''' is actually present at '''index 7'''.

As '''null element '''is already created, the output shows that '''Index 7 '''is present after '''null '''comparison.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display slide 13
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| So, remember this.

'''day at index 7 '''''not equal to '''''null '''is a wrong way to check the presence of an '''element'''.

It will create a '''null element '''at '''index 7'''.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display slide 14
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Instead, we have to use the '''in operator.'''

It will not create any extra '''element''' in the '''array.'''

This brings us to the end of this tutorial.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 17

Summary
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| In this tutorial we learnt about-

* '''Arrays''' in '''awk'''
* Assigning '''array elements'''
* How it is different from '''arrays''' in other programming languages
* Refer the '''elements '''of an '''array '''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 18

Assignment

| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| As an assignment-

* Define an '''array flowerColor'''
* Index will be the names of the flowers
* Value will be the corresponding color of the flowers
* Insert entries for any five flowers of your choice
* Print the color of the fourth flower
* Check if the flower “Lotus” is present in the '''array'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 19

Assignment(Cont.)

| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| * Insert entries for any five flowers of your choice
* Print the color of the fourth flower
* Check if the flower “Lotus” is present in the '''array'''

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 21

About Spoken Tutorial project
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| The video at the following link summarises the Spoken Tutorial project.

Please download and watch it.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 22

Spoken Tutorial workshops
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| The '''Spoken Tutorial Project''' team conducts workshops using spoken tutorials.

And gives certificates on passing online tests.

For more details, please write to us.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 23

Forum for specific questions:
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Please post your timed queries in this forum.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Display Slide 25

Acknowledgement
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at

this link.

|-
| style="background-color:#ffffff;border-top:0.035cm solid #000001;border-bottom:0.035cm solid #000001;border-left:0.035cm solid #000001;border-right:none;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"|
| style="background-color:#ffffff;border:0.035cm solid #000001;padding-top:0cm;padding-bottom:0cm;padding-left:0.191cm;padding-right:0.191cm;"| The script has been contributed by Antara.

And this is Praveen from IIT Bombay signing off.

Thanks for joining

|}

Linux-AWK/C2/Basics-of-Single-Dimensional-Array-in-awk/English - Revision history

Nancyvarkey: Nancyvarkey moved page Linux/C3/Basics-of-Single-Dimensional-Array-in-awk/English to Linux-AWK/C2/Basics-of-Single-Dimensional-Array-in-awk/English without leaving a redirect: New series

Nancyvarkey: Nancyvarkey moved page Linux/C3/Basics-of-Single-Dimensional-Array/English to Linux/C3/Basics-of-Single-Dimensional-Array-in-awk/English without leaving a redirect

Nancyvarkey at 05:08, 16 February 2018

Antarade: Created page with "'''Title of script: Basics of single Dimensional Array in Awk''' '''Author: Antara Roy Choudhury''' '''Keywords: Array, assigning array element, referring array element, che..."

← Older revision	Revision as of 11:07, 22 March 2018
(No difference)

← Older revision	Revision as of 02:12, 23 February 2018
(No difference)