Before
we begin with learning of Perl coding programs you must be familiar with what
data types Perl support? Without knowing data type you cannot go any further in
Perl programming. Let’s have a look at data type provided by Perl.
Also
Read:Setup Perl Development Tool And Software
Perl
is loosely type language and there is no need to specify the type for the
variable. The Perl interpreter automatically selects the data type based on
context of data itself. Perl support 3 Basic data types:
- Scalar:
Scalar is simple data type you can use in Perl programming. They are used as variable in the program. It is easy to identify Scalar type since they start with $ sign as prefix. A scalar type can hold the value of String, Number or a reference of variable. They are mostly used as variables and they have their scope limits too. We will see in details in upcoming chapters.
Example :
$a="abc"; #String Scalar
$num=10; #Numerical Scalar
$b=$$a; #It store reference of a in scalar variable $b - Arrays:
Arrays are ordered list of scalar that can access of data in numerical index sequence start from 0.Arrays also can be easily identified since they start with @ sign as prefix. You can also access their particular index value using Scalar types.
Example:
@a={“ABC”,”XYZ”}; #Array contain String value - Hashes:
Hashes are unordered list of Key and value pair. In hashes data can be access using key as subscript. They are also easy to identify them since they start with % sign as prefix.
Example:
%data = ('John Paul', 45, 'Lisa', 30, 'Kumar', 40);
Numeric Literals
Perl
store numeric literals internally as signed integers or double precision
floating point values. Numeric literals are as follows in Perl.
|
Type
|
Value
|
|
Integer
|
1234
|
|
Negative Int
|
-1234
|
|
Scientific Notation
|
12.6E14
|
|
Octal
|
0xffff
|
|
Hexadecimal
|
0577
|
Escape Sequence:
Escape
sequences are special character then used in any other language like HTML and
other languages. But you have to user it with double quote “” or else it will
not be interpolated. Here is list commonly of escape sequences and their work:
|
Escape sequence
|
Functioning
|
|
\\
|
Backslash Character
|
|
\a
|
Alert or beep sound
|
|
\b
|
Backspace character
|
|
\n
|
Newline character
|
|
\u
|
Force next character to uppercase
|
|
\U
|
Force all following characters to uppercase
|
|
\l
|
Force next character to lowercase
|
|
\L
|
Force all following characters to lowercase
|
|
\t
|
Horizontal tab
|
|
\v
|
Vertical tab
|
Example:
Make
one file like with name you like and make sure it’s extension as .pl
#!/usr/bin/perl
use
strict;
use
warrning;
#this
is interpolated exmaple of new line character .
$welcome="Welcome
to \n http://www.nothinglikeeverything.com/";
#this
is non-interpolated example of newline character.
$welcome='Welcome
to \n http://www.nothinglikeeverything.com/';
#This
statement will produce beep
$beep="\a
This statement will cause beep";
#This
make enitre statement capital formated
$str="\U
Hi user I hope you are undertanding what I am doing";
#This
make enite statement in lowrcase format
$lower="\L
HI USER I KNOW BIT DIFFCULT BUT IT ALL MAKE SENSE AT THE END";
#This
will make horizontal and verical tab space
$space="Here
is \t Hirizontal tab \t and here is \v verticle tab ";
OUTPUT:
Welcome
to
http://www.nothinglikeeverything.com/
Welcome
to \n http://www.nothinglikeeverything.com/ This statement will cause beep
HI
USER I HOPE YOU ARE UNDERTANDING WHAT I AM DOING
hi
user i know bit diffcult but it all make sense at the end
Here
is Hirizontal tab
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