Hash value not being interpolated

[evillen]

Hi

Please help, I can't figure out why my hash value not being
interpolated correctly?

code snippet:
begin
-------
@symbol_data = (CONN_UMP_3MM_SMT, sym.req:0554,
lib.name:conn_ump_3mm_smt, height:3.00mm, used:01ATiss1/Whitney RF,
(rev:2,NJH,26/05/04));
$symbols_and_data{$symbol_data[0]} = @symbol_data;
print "\$symbol_data[0] is: $symbol_data[0]\n";
print "Hash value is currently: $symbols_and_data{$symbol_data[0]}\n";
-------
end

description of problem:

I have the following array which has six elements:
@symbol_data = (CONN_UMP_3MM_SMT, sym.req:0554,
lib.name:conn_ump_3mm_smt, height:3.00mm, used:01ATiss1/Whitney RF,
(rev:2,NJH,26/05/04))


So far so good, I then dynamically declare and assign a hash key:
$symbols_and_data{$symbol_data[0]} = @symbol_data; #Create a Hash with
symbol name as key and data as value


Then I want to check a value:
print "\$symbol_data[0] is: $symbol_data[0]\n";

that produces this:
"$symbol_data[0] is: CONN_UMP_3MM_SMT"


Finally I want to see my hash key's values:
print "Hash value is currently: $symbols_and_data{$symbol_data[0]}\n";


that produces this:
"Hash value is currently: 6"
this appears to be the number of elements, rather than the values of
the elements.


I am expecting to see this:
"Hash value is currently: CONN_UMP_3MM_SMT, sym.req:0554,
lib.name:conn_ump_3mm_smt, height:3.00mm, used:01ATiss1/Whitney RF,
rev:2,NJH,26/05/04"

Sorry about the horrible Google formatting - I am looking into a proper
Usenet service...

Many thanks
Len

 

[mjl69]

Hi

Please help, I can't figure out why my hash value not being
interpolated correctly?

print "Hash value is currently: $symbols_and_data{$symbol_data[0]}\n";

try

print "Hash value is currently: '
.$symbols_and_data{$symbol_data[0]}.
"\n";

Try News.Individual.NET

 

[xhoster]

Hi

Please help, I can't figure out why my hash value not being
interpolated correctly?

The problem is that your hash value is not being assigned correctly.

$symbols_and_data{$symbol_data[0]} = @symbol_data;

The left hand side is a scalar. Which means the right hand side
is interpreted in scalar context. Using an array in scalar context
yields the length of the array.

$symbols_and_data{$symbol_data[0]} = \@symbol_data;
or
$symbols_and_data{$symbol_data[0]} = [@symbol_data];
or
@{$symbols_and_data{$symbol_data[0]}} = @symbol_data;

Read up on perl references and data structures (perldoc perlref,
perldoc perldata, etc.).

BTW, it doesn't look like you are using warnings or strict. Do so.

Xho

 

[Tad McClellan]

Please help,

Please show actual Perl code.

I can't figure out why my hash value not being
interpolated correctly?

The code does not even compile, so speaking of its output
is premature.

@symbol_data = (CONN_UMP_3MM_SMT, sym.req:0554,
lib.name:conn_ump_3mm_smt, height:3.00mm, used:01ATiss1/Whitney RF,
(rev:2,NJH,26/05/04));

Bareword found where operator expected at temp line 6, near "3.00mm"
(Missing operator before mm?)
Bareword found where operator expected at temp line 6, near "01ATiss1"
(Missing operator before ATiss1?)
syntax error at temp line 5, near "req:"
temp had compilation errors.


You should put quotes around your strings.

 

[evillen]

Hi

Please help, I can't figure out why my hash value not being
interpolated correctly?

The problem is that your hash value is not being assigned correctly.

$symbols_and_data{$symbol_data[0]} = @symbol_data;

The left hand side is a scalar. Which means the right hand side
is interpreted in scalar context. Using an array in scalar context
yields the length of the array.

$symbols_and_data{$symbol_data[0]} = \@symbol_data;
or
$symbols_and_data{$symbol_data[0]} = [@symbol_data];
or
@{$symbols_and_data{$symbol_data[0]}} = @symbol_data;

Read up on perl references and data structures (perldoc perlref,
perldoc perldata, etc.).

BTW, it doesn't look like you are using warnings or strict. Do so.

Xho

Hi Xho

Unfortunately when I use any of the assignments that you suggest I get
the following:

"Hash value is currently: ARRAY(0x1837f84)"

Any ideas?

Thanks for your help
Len

 

[Leendert Bottelberghs]

Unfortunately when I use any of the assignments that you suggest I get
the following:

"Hash value is currently: ARRAY(0x1837f84)"

That is the correct output for that line.
If you used:
$symbols_and_data{$symbol_data[0]} = \@symbol_data;

then the value of $symbols_and_data{$symbol_data[0]} is a reference to the
@symbol_data array. In order to print all elements of this array, first
"dereference" it (sort of type-casting), and then convert the array into a
string of elements. E.g.

print "Elements in this hash key are: ".join(', ',
@{$symbols_and_data{$symbol_data[0]}})."\n";

Notice that in the join function [syntax = join($string, @array)], the
array reference is "dereferenced" as follows:

@{$array_ref}
e.g.
@{$symbols_and_data{$symbol_data[0]}}

This array can then be used in the join.

-leendert bottelberghs

 

[evillen]

Thanks Leendert

I realised what I was doing and produced:

###################
#! perl -w
use strict;

my $aref;
my %symbols_and_data;
my @symbol_data = ("CONN_UMP_3MM_SMT", "sym.req:0554",
"lib.name:conn_ump_3mm_smt", "height:3.00mm", "used:01ATiss1/Whitney
RF", "rev:2,NJH,26/05/04");

$aref = \@symbol_data;
$symbols_and_data{$symbol_data[0]} = $aref;

print @{$symbols_and_data{$symbol_data[0]}};
####################

Which works, but your suggestion looks more suitable - I'll try it out.

Many thanks
Len