Variable interpolation

[RPrinceton]

Hi,
In the book "Learning Perl" it appears that the language supports variable interpolation. What I want to do is dynamically change the name of a variable in a loop so that when the Perl interpreter sees it, it will appear to have a new name with each iteration. Please review the following code that is not working.
my $i; # field name index
my $base = ""; #base field name
my $base1 = "abc";
my $base2 - "def"
while ($i <= 1)
{
$i = $i + 1;
$base = '$base'.$i;
print LOG &quot;Field: $base\n&quot;;
^
|__ I would think 1st iteration would
be named $base1 and in the log &quot;abc&quot;
2nd iteration would be named $base2
and in the log &quot;def&quot;
}
Here is what I end up in the log:
Field: $base1
Field: $base2
I am sure there is a little &quot;tweak&quot; to accomplish this.
Please advise.
Thanks in advance.
Regards,
Randall Princeton

 

[siberian]

Maybe this is the tweak you need :

$var1 = &quot;Var 1&quot; ;
$var2 = &quot;Var 2&quot; ;

for(1..2){
$varname = &quot;var&quot;.$_ ;
print ${ &quot;varname&quot; } ;
}


Hope this helps.

 

[RPrinceton]

Hi Siberian,
Thanks for your help!
I cut and pasted your example directly into my program and adjusted the for(1..2) to for(2) and the print statement to print LOG ${&quot;varname&quot;}; so I can drive the results to my log file. In my log file I end up with var1 and var2 instead of &quot;var 1&quot; and &quot;var 2&quot; respectively. This tells me that the variable value is not being substituted. Is there something additional that must be coded? Please advise.
Thanks in advance.
Regards,
Randall Princeton

 

[siberian]

Oops use :

print ${ &quot;$varname&quot; }

instead of

print ${ &quot;varname&quot; } ;


Sorry about that! You need to derefence the full variable contents into another variable name. Doh!

---full script--
$var1 = &quot;I am number 1!&quot; ;
$var2 = &quot;So what, I am number 2!&quot; ;

for(1..2){
$varname = &quot;var&quot;.$_ ;
$var1 = &quot;I am number 1!&quot; ;
$var2 = &quot;So what, I am number 2!&quot; ;

for(1..2){
$varname = &quot;var&quot;.$_ ;
print ${ &quot;$varname&quot; },&quot;\n&quot; ;
}

 

[RPrinceton]

Hi Siberian,
Thanks again.
I have made the modification i.e.,
print ${ &quot;$varname&quot; }
instead of
print ${ &quot;varname&quot;}

to my script and now in my log file the variables contain empty strings. Any other ideas?
Please advise.
Thanks in advance.
Regards,
Randall Princeton

 

[siberian]

Paste your full script, I think you are probably using the wrong variable names or some such thing.

Thanks

 

[RPrinceton]

Good morning Siberian,
You are absolutly right! After reviewing my script I had
variables var1 and var2 defined with 'my' in another part of the script. Once I removed the &quot;my instantiations the script worked properly. You are a life saver! I will now be able to dynamically create variable names and process 80 database fields having column names like col1, col2 col3 etc. in a loop structure.
Thanks again for your help.
Regards,
Randall Princeton