I've been given some code to look at and "solve".
foreach $field (keys %$exam)
The code above is the area I’m having difficulty in understanding. I thought $ was scalar and % was a hash, so what is %$?
$exam = {a=>1, b=>2}; # anonym hash, $exam is ref for this hash
In order to use this ref like hash you have to use dereferencing operator % before ref
foreach $field (keys %$exam)
For example the same for array ref.
$a = [1,2,3,4]; # anonym arr, $a is ref for this array
So that you have to use operator @ before ref $a for dereferencing
foreach $element (@$a) {print $element;}