Let us learn Perl scripting with examples. Here is the first Perl script example with Perl function lc (to convert a string to lower case) and Perl function uc (to convert a string to upper case):
# Perl code example
# First, implement Perl basics.
use strict; # Perl use strict finds any error in the Perl code if found, stops running the code.
use warnings; # Perl use warnings gives a warning if there is any problem with the Perl code.
use feature qw(say); # say is better than Perl print statement because it appends a newline automatically.
# Perl my to declare a variable in Perl
my $blog = "Software Testing Space";
# string functions in Perl
# Perl print variable in lowercase
say "The blog name in lower case is ", lc($blog);
# Perl uppercase or Perl uc string function
say "The blog name in upper case is ", uc($blog);
Here is another Perl scripting example with length Perl function, Perl string operations and index Perl function (to find a substring within a Perl string):
# Perl code example
use strict; # Perl use strict
use warnings; # Perl use warnings
# use strict and use warnings help us write the correct Perl code in Perl programming.
use feature qw(say); # better form of Perl print
# Perl basics are addressed above. Now, write the actual Perl code.
my $name = "Inder P Singh"; # string assignment
say "The length of name, including spaces, is ", length($name);
# Perl expression of string multiplication using x string operator
# . is string the string operator for concatenation
say "The repeated name is ". $name x 3;
my $text = "abcdef";
# Perl find by index; The indexes are 0-based, meaning they start from 0.
say "The string de occurs in text at ", index($text, "de");
#index string function returns -1 if the substring is missing in the string.
say "The string x occurs in text at ", index($text, "x");
Here is another Perl example with join Perl function, reverse Perl function and Perl split:
# Perl code example
use strict;
use warnings;
use feature qw(say);
# Perl my
my $blog = "Software Testing Space";
# An array variable in Perl can store a list of values.
my @letters = ("a".."j");# An array is declared within parentheses as a range.
# Perl print array; a Perl array is 0-based.
say "The first five letters are ", @letters[0..4]; # Print the first 5 elements of the array.
# join string function returns the joined string with a separator.
say "The joined letters are ", join(":",@letters);
# reverse string function returns the string with the characters in reverse order.
say "The reverse of letters is ", reverse(@letters);
# Based on a pattern, the split function in Perl returns a list of strings.
# The pattern in Perl split is given within a pair of forward slashes.
# The pattern is a single space character below.
say "The words in the blog are ", split(/ /,$blog); # Perl split
# Split command in Perl with another Perl example, using join with Perl split
say "The comma separated words in the blog are ", join(",",split(/ /,$blog)); # Perl split command
