Difference between revisions of "PERL/C2/for-for-each-loops/English"

for loop in Perl and

foreach loop in Perl

I will also be using the gedit Text Editor.

You can use any text editor of your choice.

If not, please go through the relevant spoken tutorials on the spoken tutorial website.

for loop

foreach loop

while loop &

do-while loop

In this tutorial, we'll cover for and foreach loop.

for (variable initialization; condition; increment/decrement)

{

Piece of code to be executed multiple times

}

for space open bracket variable initialization semicolon condition semicolon increment close bracket

Press Enter

Open curly brackets

Piece of code to be executed multiple times

Close curly brackets

gedit forLoop.pl &

and press Enter.

gedit forLoop.pl space & (ampersand)

and press Enter

#!/usr/bin/perl

for ($i=0; $i<=4; $i++) {

print “Value of i: $i\n”;

}

hash exclamation mark slash u s r slash bin slash perl

Press Enter

for space open bracket dollar i equals to zero semicolon space dollar i less than or equal to four semicolon space dollar i plus plus close bracket

space

Open curly bracket

press enter , type

print space double quote Value of i colon space dollar I slash n double quote complete semicolon

And Press Enter

now

ANd Close curly bracket

The variable i is initialized to zero.

In this case, the condition is i is less than or equal to 4.

If this condition is true, the code within the curly bracket will be executed.

“Value of i: 0”

will be displayed on the terminal.

This loop will exit when the value of i becomes greater than 4.

which is a total of 5 times.

perl hyphen c forLoop dot pl

and press Enter.

forLoop.pl syntax OK

forLoop.pl syntax OK

So, we have no errors.

perl forLoop.pl

perl forLoop dot pl

and press Enter.

Value of i: 0

Value of i: 1

Value of i: 2

Value of i: 3

Value of i: 4

foreach $variable (@array) {

perform action on each element of an array

}

foreach space dollar variable space within brackets at the rate array

space

open curly bracket

perform action on each element of an array

Press Enter

Close the curly bracket.

Please note: We'll cover array, array initialization and defining an array in subsequent tutorials.

gedit foreachLoop.pl &

and press Enter.

gedit foreachLoop dot pl space ampersand

and Press Enter

@myarray = (10, 20, 30);

foreach $var (@myarray) {

print “Element of array is: $var \n”;

}

hash exclamation mark slash u s r slash bin slash perl

and Press Enter

at the rate myarray is equal to open bracket ten comma space twenty comma space thirty close bracket semicolon

press enter

foreach space dollar var space open bracket at the rate myarray close bracket space

Open curly bracket

press enter and type

print space double quote Element of array is colon dollar var space slash n double quote complete semicolon

Press Enter and

Close curly bracket

@myarray = (10, 20, 30);

An array myarray is declared.

It has 3 elements 10, 20 and 30.

Then 20 and so on, till all the elements are printed.

perl -c foreachLoop.pl

type

perl hyphen c foreachLoop dot pl

and press Enter.

foreachLoop.pl syntax OK

perl foreachLoop.pl

So let us execute the Perl script. Type

perl foreachLoop dot pl

and press Enter

Element of an array is: 10

Element of an array is: 20

Element of an array is: 30

In this tutorial, we have learnt -

for loop and

foreach loop in Perl

using some sample programs.

1. Declare a string as 'Spoken Tutorial' and
2. Print it 5 times
3. Declare an array of colours as @colorArray = ('red', 'white', 'blue') and
4. Print the element of an array using foreach loop

It summaries the Spoken Tutorial project

If you do not have good bandwidth, you can

download and watch it

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

http://spoken-tutorial.org\NMEICT-Intro

Teacher project

It is supported by the National Mission on

Education through ICT, MHRD, Government of India.

More information on this Mission is available

spoken hypen tutorial dot org slash NMEICT hyphen Intro

This is Amol Brahmankar signing off.

Thanks for joining.