update array doc.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
update undefined doc.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
update variable doc.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
Merge pull request #8 from appleboy/patch

感謝修正。