The weekly challenge 379 - Task 1: Reverse String

 1 #!/usr/bin/env perl
 2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-379/#TASK1
 3 #
 4 # Task 1: Reverse String
 5 # ======================
 6 #
 7 # You are given a string.
 8 #
 9 # Write a script to reverse the given string without using standard reverse
10 # function.
11 #
12 ## Example 1
13 ##
14 ## Input: $str = ""
15 ## Output: ""
16 #
17 ## Example 2
18 ##
19 ## Input: $str = "reverse the given string"
20 ## Output: "gnirts nevig eht esrever"
21 #
22 ## Example 3
23 ##
24 ## Input: $str = "Perl is Awesome"
25 ## Output: "emosewA si lreP"
26 #
27 ## Example 4
28 ##
29 ## Input: $str = "v1.0.0-Beta!"
30 ## Output: "!ateB-0.0.1v"
31 #
32 ## Example 5
33 ##
34 ## Input: $str = "racecar"
35 ## Output: "racecar"
36 #
37 ############################################################
38 ##
39 ## discussion
40 ##
41 ############################################################
42 #
43 # Since we can't use reverse(), we just cut the first character as
44 # long as the string still has characters, and put it in front of
45 # the result string.
46 
47 use v5.36;
48 
49 reverse_string("");
50 reverse_string("reverse the given string");
51 reverse_string("Perl is Awesome");
52 reverse_string("v1.0.0-Beta!");
53 reverse_string("racecar");
54 
55 sub reverse_string($str) {
56    say "Input: \"$str\"";
57    my $result = "";
58    while(length($str) > 0) {
59       $str =~ s/(.)//;
60       $result = $1 . $result;
61    }
62    say "Output: \"$result\"";
63 }