Re: Re: Interchanging hash values

Why make two passes?

D:\Perl\test>perl
use strict;
use warnings;

my %h; @h{'a'..'j'} = 0..9;
print %h, $/;

my ($min,$max) = (keys %h);
($min,$max) = ( $h{$min} < $h{$_} ? $min : $_, $h{$max} > $h{$_} ? $ma
+x : $_ ) for keys %h;

@h{$min,$max} = @h{$max,$min};
print %h, $/;

^Z
a0b1c2d3e4f5g6h7i8j9
a9b1c2d3e4f5g6h7i8j0
[download]

Examine what is said, not who speaks.

1) When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
2) The only way of discovering the limits of the possible is to venture a little way past them into the impossible
3) Any sufficiently advanced technology is indistinguishable from magic.
Arthur C. Clarke.

Comment on Re: Re: Interchanging hash values Download Code

Replies are listed 'Best First'.

Re^3: Interchanging hash values (single pass - or not)
by Aristotle (Chancellor) on Apr 21, 2003 at 11:39 UTC

List::Util

my ($min, $max) = (scalar each %h) x 2;
($min, $max) = (
    $h{$_} < $h{$min} ? ($_, $max) :
    $h{$_} > $h{$max} ? ($min, $_) :
    ($min, $max)
) for keys %h;
[download]

each

my $min = each %h;
my $max = each %h;

if(defined $max) {
    local $_;
    ($min, $max) = (
        $h{$_} < $h{$min} ? ($_, $max) :
        $h{$_} > $h{$max} ? ($min, $_) :
        ($min, $max)
    ) while defined($_ = each %h);
}
else {
    $max = $min;
}
[download]

Makeshifts last the longest.

[reply]
[d/l]
[select]


Do you know where your variables are?
	PerlMonks