For fun, here's something that works with non-lexical arrays:

sub get_ref {
   my ($type, $varname) = @_;
   return do { no strict 'refs'; *$varname{$type} };
}

@array2;
@array3 = ();
@array4 = (undef);
@array5 = ('one');
@bla::array6;

$\=$/;
print('array1: ', defined(get_ref(ARRAY => 'array1     '))?1:0);  # 0
print('array2: ', defined(get_ref(ARRAY => 'array2'     ))?1:0);  # 1
print('array3: ', defined(get_ref(ARRAY => 'array3'     ))?1:0);  # 1
print('array4: ', defined(get_ref(ARRAY => 'array4'     ))?1:0);  # 1
print('array5: ', defined(get_ref(ARRAY => 'array5'     ))?1:0);  # 1
print('array6: ', defined(get_ref(ARRAY => 'bla::array6'))?1:0);  # 1
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