ok thanks for your input. I corrected the problem in a doofangled way.. I passed type by reference to the function and only returned the hash. I don't know if I like it but it works atm. Here is my next question. If I get a scalar hashref back from that function like so, $mynewref = findResults()
do i simply pass that ref to another function who needs access to the hash data. ie. assignResultSet($mynewref); and then simply treat it as a hashref inside the sub? I wouldn't think you would pass it as a ref again because then you would need to doubly deref it unless i'm mistaken. That is my hunch but I'm not sure if that's the correct/accepted way to do it
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ok thanks for your input. I corrected the problem in a doofangled way.. I passed type by reference to the function and only returned the hash. I don't know if I like it but it works atm.
Be careful about what you pass around, and what you return. As others already said, your parameter list gets flattened out into a list. If you return a hash, the hash gets flattened out, but if you accept the results of the call back into hash, then you are all right. NOTE: This all changes if you have a hash as one of many parameters that you are passing to a subroutine, or returning from a subroutine. If you are passing mixed parameters (scalars, lists, hashs), then your subroutine can get confused.
The safest way to pass (or return) arrays and hashes is by reference. This keeps your parameter list all scalars, since a reference is a scalar.
sub test {
my $scalar1 = shift;
my $array2_ref = shift;
my $hash3_ref = shift;
### if you want to work with the hash, and not just
### the hash reference, then dereference the ref.
my %hash3 = %$hash3_ref;
print "value for hash key 'one' is $hash3{'one'}\n";
### I prefer to just use the reference instead, and
### not create the hash by dereferencing the hash ref.
print "value for hash key 'one' is $hash3_ref->{'one'}\n";
return($scalar1, $array2_ref, $hash3_ref);
}
my $test_scalar = "abc";
my @test_array = ( "a", "b", "c" );
my %test_hash = ( "a" => 1,
"b" => 2,
"c" => 3 );
($new_scalar, $new_arrayref, $new_hashref) = test($test_scalar, \@test
+_array, \%test_hash);
Sorry, now that I've preview'd my response, I can't see what your next question was.
HTH. | [reply]
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fyi, exactly what I did was this
my $type;
%results = findResults(\$type);
$type is then modified inside findResults() but only the hash is passed back to the caller. So the value of $type is changed but never passed back,so as to avoid slurpage
Is this ok style? or is that a little too C++?
You can return only a scalar or a list from a function. To get a hash return, you either have to flatten it into a list (and reconstruct it at the other side) or return a reference to the hash I haven't found this to be so, unless perl is taking care of the reconstruction for me. I returned a hash like so return %results; and the calling hash was populated correctly. I was able to do a foreach over each of the keys i had set. Perl is taking care of the reconstruction correct? | [reply]
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