What are Perl String Literals?

PERLServer Side ProgrammingProgramming Scripts

Strings are sequences of characters. They are usually alphanumeric values delimited by either single (') or double (") quotes. They work much like UNIX shell quotes where you can use single-quoted strings and double-quoted strings.

Double-quoted string literals allow variable interpolation, and single-quoted strings are not. There are certain characters when they are proceeded by a backslash, have special meaning and they are used to represent like newline (\n) or tab (\t).

You can embed newlines or any of the following Escape sequences directly in your double-quoted strings −

Escape sequenceMeaning
\'Single quote
\"Double quote
\aAlert or bell
\fForm feed
\rCarriage return
\tHorizontal tab
\vVertical tab
\0nnCreates Octal formatted numbers
\xnnCreates Hexideciamal formatted numbers
\cXControls characters, x may be any character
\uForces next character to uppercase
\lForces next character to lowercase
\UForces all following characters to uppercase
\LForces all following characters to lowercase
\QBackslash all following non-alphanumeric characters
\EEnd \U, \L, or \Q


Let's see again how strings behave with a single quotation and double quotation. Here we will use string escapes mentioned in the above table and will make use of the scalar variable to assign string values.

 Live Demo

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

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

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

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

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

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


This will produce the following result −

Welcome to
Welcome to \ntutorialspoint.com!
Welcome to tutorialspoint.com!
Welcome to TUTORIALSPOINT.com!
Welcome\ to\ tutorialspoint\'s\ family
Published on 28-Nov-2019 12:28:55