Thursday, May 29, 2008

Perl: Invoke variable using other variable

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At my last post I have mentioned how to invoke a Perl function using a variable. Today i'm going to tell how to invoke a variable using other variable. For example below example.

## Initially
$variable = "Before";
print "$variable\n";

## Take the variable name into another
$variable_name = "variable";
## Invoking the value using other variable
${$variable_name} = "Now";
print "$variable\n";
If you need to use array invoke using a variable, then below code example.
## Initially the array
@variable = qw( Before After);
print "@variable\n";

## Take the array name into another variable
$variable_name = "variable";
## Invoking the array using other variable
@{$variable_name} = qw(All have changed);
print "@variable\n";
Infact you can use Hash also for this purpose. But remember as I told you that this example doesn't work when strict is used. May be there is a way for strict, but I don't know.

1 comment:

Randal L. Schwartz said...

This is definitely considered bad form. Don't ever consider using this in production code. You will be laughed at. Cute trick, no real application.