String is an ordered series of characters usually enclosed in single quotes (') or double quotes (“) quotations.

How to declare strings

$string_var = value; 

value should be enclosed in either single quotes ' or double quotes “.

Example

$str1 = 'Hello World! ';
$str2 = "Happy learning!!"; 

print($str1);
print($str2);

Check result here

String Functions

Below are some of the useful string functions in Perl.

String Function	Description
length	This function is used to return the number of characters of a given string
substr	This method is used to modify a substring in a string
index	Searches for a substring in the given string and returns the position of the first occurrence of the substring if found
rindex	Similar to index but searches for a substring from right to left
reverse	This function is used to reverse a string
lc	This function is used to convert the specified string to lowercase
uc	This function is used to convert the specified string to uppercase
crypt	This function is used to encrypt password
q/string/	used to create single-quoted strings
qq/string/	used to create double-quoted strings
chr	to return ASCII or UNICODE character of a number
hex	used to convert a hexadecimal string to it's equivalent decimal value
oct	used to convert an octal number to it's equivalent decimal value
ord	returns the ASCII value of the first character of a string
sprintf	Formats string provided by the user and returns the formatted string to be used with print()

Example

#!/usr/bin/perl
use warnings;
use strict;

# Find the length of a string
my $str = "Hello world! Happy learning!!";
print(length($str),"\n"); 

# extract substring from a string
my $substr1  = substr($str, 0, 5);   
my $substr2    = substr($str, -10);     
 
print($substr1,"\n");
print($substr2,"\n");
 
my $i = "Happy";
my $p = index($str,$i); 
print(qq\Index of substring "$i" is "$p" in the string: "$str"\,"\n");

print("Upper case of the string:\n");
print(uc($str),"\n");
 
print("Lower case of the string:\n");
print(lc($str),"\n");

Check result here