what does perl operator “||=” do?

Question

What does the operator ||= do in perl?

to be more specific if you have a code like:

my ($my_link);
$my_link  ||= DownloadF($file,\'l\') if          


        

Answer 1

it means if $my_link is nil/has no value, then assign it this value with = (value)

if $my_link already has a value, then it don't do anything