The weekly challenge 311 - Task 1: Upper Lower

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-311/#TASK1
 3 #
 4 # Task 1: Upper Lower
 5 # ===================
 6 #
 7 # You are given a string consists of english letters only.
 8 #
 9 # Write a script to convert lower case to upper and upper case to lower in the
10 # given string.
11 #
12 ## Example 1
13 ##
14 ## Input: $str = "pERl"
15 ## Output: "PerL"
16 #
17 ## Example 2
18 ##
19 ## Input: $str = "rakU"
20 ## Output: "RAKu"
21 #
22 ## Example 3
23 ##
24 ## Input: $str = "PyThOn"
25 ## Output: "pYtHoN"
26 #
27 ############################################################
28 ##
29 ## discussion
30 ##
31 ############################################################
32 #
33 # The tr/// operator allows us to swap in one step, so let's
34 # just use that.
35 
36 
37 use v5.36;
38 
39 foreach ( qw(pERl rakU PyThOn) ) {
40         say "Input: $_, Output: " . upper_lower($_);
41 }
42 
43 sub upper_lower {
44         my $str = shift;
45         $str =~ tr/a-zA-Z/A-Za-z/;
46         return $str;
47 }
48