Perl Variables

There are three types of variables in perl: Scalar, arrays of scalars and hashes. Lets learn them one by one with the help of examples.

Scalars

Scalars are single data unit. A scalar can be integer, float, string etc. Scalar variables are prefixed with “$” sign. Lets have a look at the following perl script where we have three scalar variables.

#!/usr/bin/perl

# Integer
$age = 29;

# String
$name = "Chaitanya Singh";

# Float
$height = 180.88;

print "Name: $name\n";
print "Age: $age\n";
print "Height: $height\n";

Output:

Name: Chaitanya Singh
Age: 29
Height: 180.88

Arrays

Arrays are ordered list of scalars, Array variables are prefixed with “@” sign as shown in the example below:

#!/usr/bin/perl

@friends = ("Ajeet", "Leo", "Rahul", "Dhruv");

print "\$friends[0] = $friends[0]\n";
print "\$friends[1] = $friends[1]\n";
print "\$friends[2] = $friends[2]\n";
print "\$friends[3] = $friends[3]\n";

Output:

$friends[0] = Ajeet
$friends[1] = Leo
$friends[2] = Rahul
$friends[3] = Dhruv

Hashes (also known as associative arrays)

Hashes are group of key-value pairs. Hash variables are prefixed with “%” sign. Lets have a look at the example below:

#!/usr/bin/perl

%age = ('Chaitanya Singh', 29, 'Ajeet', 28, 'Lisa', 25);

print "\$age{'Lisa'}: $age{'Lisa'}\n";
print "\$age{'Chaitanya Singh'}: $age{'Chaitanya Singh'}\n";
print "\$age{'Ajeet'}: $age{'Ajeet'}\n";

Output:

$age{'Lisa'}: 25
$age{'Chaitanya Singh'}: 29
$age{'Ajeet'}: 28