Global symbol requires explicit package name

Question

Global symbol requires explicit package name? Why has this occurred and what are various cases that can cause this error?

Answer 1

It may also happen when the statement before is not complete.

use strict;  sub test;  test()  # some comment my $x; 

perl now complains with following error message:

my " Global symbol "$x" requires explicit package name 

The error is not in the declaration of "my", but at the missing semicolon (;) at test().