Assigning a hash by reference

[audiopro]

I have the following code

my $EMES='$'.$TABLE_NAME[$WHICH_TABLE];
$EMES.='_COMMENT';
$EMES.="{'EMAIL'}";
print "em - $EMES<BR>";

Which produces a hash reference

em - $CUSTOMERS_COMMENT{'EMAIL'}

I am trying to execute code

$CUSTOMERS_COMMENT{'EMAIL'}="A Message";

but cannot work out how to assign the hash, using $EMES.
I think I must call $EMES as a reference but what is the syntax?

$EMES="A Message" # assigns new value,
\$EMES="A Message" # throws a dizzy fit

I know it should be simple but my head hurts


Keith

 

[stevexff]

If you are going to build up the variable name in this way you will need eval. Cue ishnid for a reference to his famous FAQ on why you shouldn't do this. Alternative could be:

my %table_comments;
$table_comments{$TABLE_NAME[$WHICH_TABLE]}->{'EMAIL'} = "A message";

print "em - ", $table_comments{$TABLE_NAME[$WHICH_TABLE]}->{'EMAIL'}, "<BR>";

Steve

[small]"Every program can be reduced by one instruction, and every program has at least one bug. Therefore, any program can be reduced to one instruction which doesn't work." (Object:erlDesignPatterns)[/small]

 

[audiopro]

Thanks for that, I wouldn't want the Ishnid monster to vent his wrath in my direction.
I have had a rethink and solved the problem another way. I have a number of MySQL tables and had created a seperate hash for each table, to create form field user notes. The solution was to create only 1 hash and then assign just the key section to the name of the form field. The added bonus is that the code is simplified too.


Keith

 

[stevexff]

Glad you got it sorted out. Usually (unless you are working with a *really* primitive language) if you ever find yourself constructing variable names on the fly, it normally means you're doing it wrong and there is a better way to do it. In perl, the better solution usually involves hashes.

Steve

[small]"Every program can be reduced by one instruction, and every program has at least one bug. Therefore, any program can be reduced to one instruction which doesn't work." (Object:erlDesignPatterns)[/small]