Freeing up memory by undefining perl variables

[pavanponnapalli]

hi,
What is the difference between undef($variable _name) and
$vaiable_name = undef;? And is there any function in perl which dynamically deallocates the allocated memory for scalars? same question for lists and hashes.

Thanks & Regards,
Pavan Kumar

[KevinADC]

undef(variable) completely deletes the variable

variable = undef assigns the undef value to a variable

As far as I know if you do something like this:

$foo = 'some value';
$foo = ''; <-- frees up memory

@foo = (1..1000000);
@foo = (); <-- frees up the memory

I am not sure if you undef(variable) it will free up the memory. I don't know if there is a module that frees up memory.