Solution: sort scores - video

Solution: of the sort scores exercise.

examples/hashes/score_data.pl

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

my $filename = shift or die "Usage: $0 FILENAME\n";

open(my $fh, "<", $filename) or die "Could not open '$filename'\n";

my %score_of;
while (my $line = <$fh>) {
    chomp $line;
    my ($name, $score) = split /,/, $line;
    $score_of{$name} = $score;
}

foreach my $name (sort keys %score_of) {
    printf "%-10s %s\n", $name, $score_of{$name};
}
print "--------------------------\n";

foreach my $name (sort { 
                        $score_of{$b} <=> $score_of{$a} 
                       } keys %score_of) {
    printf "%-10s %s\n", $name, $score_of{$name};
}

We run it as perl score_data.pl score_data.txt.

examples/hashes/score_data.txt

Foo,23
Bar,70
Baz,92
Bozo,17
Gozo,52
Dardon,20
Mekodra,23

The code starts with the usual hash-bang line followed by use strict; and use warnings;.

Then we get the name of the data file from the command line using shift.

Then we open the file for reading.o

Then we declare a hash called %score_of in which we are going to hold the name-value pairs from the data file.

We go over the file line-by-line using a while loop. chomp off the newline from the end of the line and the split at the comma (,).