Re^2: Getting Getopt::Long values into a hash

It only seems to work when I use it like:

$getoptret = $p->getoptions(
                            'house'   => \$my_hash->{house},
                            'dog|d:s' => \$my_hash->{mutt},
  );
[download]

what is exactly the difference between $my_hash->{something} and $my_hash{something} ?

Thanks a lot!
Luca

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Re^3: Getting Getopt::Long values into a hash by fishbot_v2 (Chaplain) on Nov 08, 2005 at 14:33 UTC
It seems that you must have `$my_hash` as a hashref, rather than having a `%my_hash`. The arrow-form adds a dereference to the LHS value. In my example, #1 and #2 are equivalent: `my $ref = { foo => "bar" }; print ${$ref}{"foo"}; #1 prints "bar" print $ref->{"foo"}; #2 prints "bar" print $ref{"foo"}; #3 prints "" # and under strictures throws a: # "Global symbol "%ref" requires explicit package name"` [download] `$ref{"foo"}` only returns a value if there is a hash named `%ref`.	[reply] [d/l] [select]
Re^4: Getting Getopt::Long values into a hash by jeanluca (Deacon) on Nov 08, 2005 at 15:21 UTC
I almost start my script with: my $my_hash = {} ; As far as I know this should create a hash reference ?! What exactly means 'dereference to the LHS value' ? When it comes to variables and references I often get confused! Thnx Luca	[reply]
Re^5: Getting Getopt::Long values into a hash by fishbot_v2 (Chaplain) on Nov 08, 2005 at 16:01 UTC
As far as I know this should create a hash reference Yes that is correct. What exactly means 'dereference to the LHS value'? LHS = left hand side. I meant that the arrow operator takes a reference on the left, and dereferences it (ie. 'replaces' it with what it points to). You can then subscript it in various ways, with a key (for a hashref), an index (arrayref), parameters (coderef), or a method (object). A hashref is not a hash, and thus you cannot access it directly. You need to first "fetch" the hash that it points to.	[reply]
Re^6: Getting Getopt::Long values into a hash by jeanluca (Deacon) on Nov 08, 2005 at 16:51 UTC