hash of arrays question

[John Gregory]

I'm new to perl and have a question. The perl book
says that hashes map keys to values. Using the reverse
function you can map values to keys. My problem is
I have a hash of arrays and I want to map an array
of values to a particular key. Is there any way to
do this?

Thanks,

John

[Skeleton Man]

Re: hash of arrays question

>I'm new to perl and have a question. The perl book[color=blue]
>says that hashes map keys to values. Using the reverse
>function you can map values to keys. My problem is
>I have a hash of arrays and I want to map an array
>of values to a particular key. Is there any way to
>do this?[/color]

There are two ways to do this:

$sample{'key1'} = ['item1', 'item2', 'item3']; # Array of values mapped to a
single hash key (note the use of square brackets [])
print $sample{'key1'}[0]; # Prints "item1"

Or:

@data = ('item4, 'item5', 'item6', 'item7'); # Create a new array
$sample{'key2'} = \@data; # Take a reference to the
array (backslash operator), you could use any existing array here too.
print $sample{'key2'} ;


Let me know if you need anything explained a little more clearly :-)

Regards,
Chris

[mzi]

Re: hash of arrays question

Skeleton Man wrote:
[color=blue][color=green]
>>I'm new to perl and have a question. The perl book
>>says that hashes map keys to values. Using the reverse
>>function you can map values to keys. My problem is
>>I have a hash of arrays and I want to map an array
>>of values to a particular key. Is there any way to
>>do this?[/color]
>
> There are two ways to do this:
>
> $sample{'key1'} = ['item1', 'item2', 'item3']; # Array of values mapped to
> a single hash key (note the use of square brackets [])
> print $sample{'key1'}[0]; # Prints "item1"
>
> Or:
>
> @data = ('item4, 'item5', 'item6', 'item7'); # Create a new array
> $sample{'key2'} = \@data; # Take a reference to the
> array (backslash operator), you could use any existing array here too.
> print $sample{'key2'} ;
>
>
> Let me know if you need anything explained a little more clearly :-)[/color]

This means: hash values can be references.

--
mzi

[Michael Gaylord]

Re: hash of arrays question

I'm new to perl and have a question. The perl book

says that hashes map keys to values. Using the reverse
function you can map values to keys.

AFAIK, the reverse function takes a list/array, and returns
it in the opposite order.

My problem is
I have a hash of arrays and I want to map an array
of values to a particular key. Is there any way to
do this?

Something like this?

@contents = (1,2,3,4,5)
$hashofarrays{k ey} = \@contents

I can then reference like follows:

print $hashofarrays{k ey}[2]

outputs: 3