how do I use a hash of hashes reference in a function ?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

This is a rephrased version of my previous question.
I can pass a hash of hashes to a function OK:

$hash{name} = {date => "00-22-00", city=>"Chicago",};


function (\%hash1);
function (\%hash2);
[download]

However I've tried several examples given previously and none work completely

sub function {
my %hashref=%{shift()};
#the below works ok
print $hashref{name}{city},"\n";
# but adding to the hash doesn't work if I print out
# the entire hash outside this function
$hashref{name}={data1=>"moredata",};
# it does work if I print it out inside the function
}
[download]

Comment on how do I use a hash of hashes reference in a function ? Select or Download Code

Replies are listed 'Best First'.
Re: how do I use a hash of hashes reference in a function ? by merlyn (Sage) on Sep 22, 2000 at 21:53 UTC
`$hashref{name}={data1=>"moredata",};` [download] Wrong syntax for adding to a hash. Use this: `$hashref{name}{data1} = "moredata";` [download]	[reply] [d/l] [select]
RE: Answer: how do I use a hash of hashes reference in a function ? by Fastolfe (Vicar) on Sep 22, 2000 at 23:45 UTC
Just for clarification (for the original poster), your syntax: `$hashref{name} = { data1 => "moredata" };` [download] replaces the reference in `$hashref{name}` with a new one, composed of your `data1 => "moredata"` hash. That's why it won't work. merlyn is correct in that if you wish to modify the hash referenced by `$hashref{name}` you don't do that by setting `$hashref{name}`, you modify it as if it were a hash: `$hashref{key}{subkey} = $xyz;`	[reply] [d/l] [select]