my $hash = { a => 'b' };
$hash->{$x}

##</code><code>##

{a => 'b'}->{$x}

##</code><code>##

sub some_function
{
    my ( $x ) = @_;
    return ( $x eq 'foo' ) ? "results for foo" :
           ( $x eq 'bar' ) ? "results for bar" :
           ( $x eq 'qaz' ) ? "results for qaz" : 
           " ... and so on, ad nauseum";
}

##</code><code>##

sub some_function
{
    my ( $x ) = @_;
    { foo => "results for foo",
      bar => "results for bar",
      qaz => "results for qaz",
    }->{$x} || "... and so on, ad nauseum";
}

##</code><code>##

#!/usr/bin/perl

use strict;
use Benchmark qw(:all);

sub anonhash
{
    my ( $x ) = @_;
    { foo => "results for foo",
      bar => "results for bar",
      qaz => "results for qaz",
    }->{$x} || "... and so on, ad nauseum";
}
sub ternary
{
    my ( $x ) = @_;
    return ( $x eq 'foo' ) ? "results for foo" :
           ( $x eq 'bar' ) ? "results for bar" :
           ( $x eq 'qaz' ) ? "results for qaz" : 
           " ... and so on, ad nauseum";
}
my @strings = qw/foo bar baz qaz/;
my $i = 0;
cmpthese( -5, {
                anonhash => sub { anonhash( $strings[$i++] );
                                  $i = 0 if ( $i == @strings ) },
                ternary => sub { ternary( $strings[$i++] );
                                 $i = 0 if ( $i == @strings ) },
               } );

##</code><code>##

             Rate anonhash  ternary
anonhash  64869/s       --     -72%
ternary  232475/s     258%       --

##</code><code>##

             Rate anonhash  ternary
anonhash  26893/s       --     -87%
ternary  204817/s     662%       --