Question

First timer…so let me know if there is anything that I have not paid attention to whilst posing a question.

The question is how to use a scalar as a condition, as the code below does not work.

my @parameter=('hub');

my %condition;
$condition{'hub'}{'1'}='$degree>=5';

foreach (@parameter) {
       if ($condition{$_}{'1'}) {..}
}

I thought that is because the condition is not interpreted correctly, so I also tried the following, which also did not work.

if ("$condition{$parameter}{'1'}") { ..}

Would really appreciate any help. 🙂

Answer 1

You either want string eval, which evaluates a string as Perl code

if (eval $condition{$_}{'1'}) { ...

or perhaps a more secure approach would be using code references

$condition{'hub'}{'1'} = sub { return $degree>=5 };

if ($condition{$_}{'1'}->()) { ...

In the second example, you are attaching a piece of code to a variable. The $var->() syntax executes the code and evaluates to the return value of the code.