Re: Hash sorting

You're handling the hash wrong. Try this:

my %calhash;
my $key = "";
my $value = "";

while (<OUTFILE>) {
    chomp;
    my ($key, $value) = split(/;/, $_);
    $calhash{$key} = $value;
}

foreach $key (sort {$b cmp $a} keys %calhash) {
    print TESTFILE "$key;$calhash{$key}\n";
}
[download]

Update: Dunno what sorting algorithm he wants. I assumed reverse alphanumeric like he typed. I didn't have enough information to change the sorting logic...

buckaduck

Comment on Re: Hash sorting Download Code

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Re: Re: Hash sorting by derby (Abbot) on Mar 13, 2002 at 18:23 UTC
Good call but doesn't he want to sort by the number of clients and not the client name? `foreach $key ( sort{ $calhash{$b} <=> $calhash{$a} } keys %calhash ) {` [download] -derby Yahoo! 100th post.	[reply] [d/l]
Re: Re: Hash sorting by jamen (Initiate) on Mar 15, 2002 at 16:25 UTC
`my %calhash; my $key = ""; my $value = ""; while (<OUTFILE>) { chomp; my ($key, $value) = split(/;/, $_); $calhash{$key} = $value; } foreach $key (sort {$b cmp $a} keys %calhash) { print TESTFILE "$key;$calhash{$key}\n"; }` [download] Thank you!!!! That worked!!! Why was the chomp placed before the split? On this line `$calhash{$key} = $value` what is that saying? Just trying to learn why I was off and my logic for it. Once again, thank you! Ben	[reply] [d/l] [select]
Re: Re: Re: Hash sorting by rdfield (Priest) on Mar 15, 2002 at 16:32 UTC
(1) the chomp was placed before the split so that the value being split didn't have a newline. With the chomp afterwards, you're removing in the newline from $_, not $value (which was populated before the chomp) (2) in your orginal code the statement read "put the value of $key into hash at key '$key'", rather than as the updated code has it. "put the value of $value into the hash at key '$key'. rdfield	[reply]
Re: Re: Re: Hash sorting by buckaduck (Chaplain) on Mar 15, 2002 at 16:53 UTC
1. The chomp comes before the split so that you remove carriage-returns from each line before you split it into $key and $value. If you don't do this, each $value will retain a trailing carriage return. Chomping the line after the split is pointless in this case, since you don't use the implicit variable `$_` again. 2. `$calhash{$key}` is the value in `%calhash` which the key `$key` points to. I'm assigning it a new value `$value`. Later, if I want the key and value again (like in the printing loop), I'll refer to `$key` and `$calhash{$key}`. The syntax for Variable Names is covered in perldata of the perl documentation. buckaduck	[reply] [d/l] [select]