Hi all, new to Perl and working through Simon Cozens free Beginning Perl book, tried to write myself a little program to test if I understood RegExp and it's not giving me the expected answers. Could anyone offer any guidance as to why the final print of $_ gives "FourThreeTwoOne, Three, Four, One, Two" please? As I said I'm only a novice, please be gentle!:)

#!/usr/bin/perl
#subs.plx
use warnings;
use strict;

#An incorrectly ordered list to have the user organise
$_ = "Three, Four, One, Two";

print ("\t\tCounting Program\n\n", $_, "\n\n");
my $correct;

print "Is this sequence correct?(yes/no)\n";
    $correct = <STDIN>;
    chomp ($correct);
    

while ($correct ne "yes"){
    print "Is the first number correct?\n";
    my $first = <STDIN>;
    chomp ($first);
    
    if ($first ne "yes"){
        print"What should it be?\n";
        $first = <STDIN>;
        chomp ($first);
        }
    
    print "Is the second number correct?\n";
    my $second = <STDIN>;
    chomp ($second);
    
    if ($second ne "yes"){
        print"What should it be?\n";
        $second = <STDIN>;
        chomp ($second);
        }
    
    print "Is the third number correct?\n";
    my $third = <STDIN>;
    chomp ($third);
    
    if ($third ne "yes"){
        print"What should it be?\n";
        $third = <STDIN>;
        chomp ($third);
        }
    
    print "Is the fourth number correct?\n";
    my $fourth = <STDIN>;
    chomp ($fourth);
    
    if ($fourth ne "yes"){
        print"What should it be?\n";
        $fourth = <STDIN>;
        chomp ($fourth);
        }

    #My RegExp
    /([A-Z][a-z][.][\b])/;
    
    #The substitutions based on my RegExp
    s/$1/$first/;
    s/$2/$second/;
    s/$3/$third/;
    s/$4/$fourth/;
    
    #Final print reads:FourThreeTwoOne, Three, Four, One, Two
    print ($_, "\n\n");
        
    print "Is this sequence correct now?(yes/no)\n";
    $correct = <STDIN>;
    chomp ($correct);            
    }

[download]

Anby guidance would be appreciated, Cheers, Keystone.

In reply to RegExp substitution by Keystone

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