[is_mobile](%E9%AA%8C%E8%AF%81/is_mobile.md) [is_positive_integer](%E9%AA%8C%E8%AF%81/is_positive_integer.md) [is_json](%E9%AA%8C%E8%AF%81/is_json.md) [is_datetime](%E9%AA%8C%E8%AF%81/is_datetime.md) [is_md5_result](%E9%AA%8C%E8%AF%81/is_md5_result.md)