[plug] Perl Question: Searching an array

[Matthew Robinson]

Brad Hill wrote:
> convert the array to a hash and then it's trivial:

You could convert the list to a hash but for a large array this would be 
a slow and memory consuming process.

The code that you have shown below does not work as you intend.

> 
> #!/usr/bin/perl
> 
> @myarray = ( "fish", "chicken", "beef" );
> %myhash = @myarray;
> print "found fash" if $myhash{"fash"};
> print "found fish" if $myhash{"fash"};

I modified your code slightly (shown below), so that it tries to find 
fish, chicken and beef and got the following output:

$ perl test.pl
Found fish
$

The code is as shown:

#!/usr/bin/perl

use strict;

my @myarray = ('fish', 'chicken', 'beef');

my %myhash = @myarray;

print "Found fish\n" if ($myhash{fish});
print "Found chicken\n" if ($myhash{chicken});
print "Found beef\n" if ($myhash{beef});

This is because the list ('fish', 'chicken', 'beef') is made into the 
following hash structure:

%myhash = (
	'fish' => 'chicken',
	'beef' => undef
);

This is clearly not what you intended.


Matt

-- 
print map{s&^(.)&\U\1&&&$_}split$,=$",(`$^Xdoc$,-qj`=~m&"(.*)"&)[0].$/