S.N.	Types and Description
1	Scalar: Scalars are simple variables. They are preceded by a dollar sign ($). A scalar is either a number, a string, or a reference. A reference is actually an address of a variable which we will see in upcoming chapters.
2	Arrays: Arrays are ordered lists of scalars that you access with a numeric index which starts with 0. They are preceded by an "at" sign (@).
3	Hashes: Hashes are unordered sets of key/value pairs that you access using the keys as subscripts. They are preceded by a percent sign (%).

Type	Value
Integer	1234
Negative integer	-100
Floating point	2000
Scientific notation	16.12E14
Hexadecimal	0xffff
Octal	0577

Escape sequence	Meaning
\\	Backslash
\'	Single quote
\"	Double quote
\a	Alert or bell
\b	Backspace
\f	Form feed
\n	Newline
\r	Carriage return
\t	Horizontal tab
\v	Vertical tab
\0nn	Creates Octal formatted numbers
\xnn	Creates Hexideciamal formatted numbers
\cX	Control characters, x may be any character
\u	Force next character to uppercase
\l	Force next character to lowercase
\U	Force all following characters to uppercase
\L	Force all following characters to lowercase
\Q	Backslash all following non-alphanumeric characters
\E	End \U, \L, or \Q

#!/usr/bin/perl

# This is case of interpolation.
$str = "Welcome to \n!";
print "$str\n";

# This is case of non-interpolation.
$str = 'Welcome to \n!';
print "$str\n";

# Only W will become upper case.
$str = "\uwelcome to !";
print "$str\n";

# Whole line will become capital.
$str = "\UWelcome to !";
print "$str\n";

# A portion of line will become capital.
$str = "Welcome to \U\E.com!"; 
print "$str\n";

# Backsalash non alpha-numeric including spaces.
$str = "\QWelcome to 's family";
print "$str\n";