CJK
lastmod 2020-10-11created 2020-10-111 edits
CJK (Chinese - Japanese - Korean) is a collective term for Korean, Chinese, and Japanese, used in the fields of software internationalization and language localization. Including Vietnamese, it is also called CJKV.
About
The languages in CJK all share the characteristic of having been influenced, at least to some degree, by Chinese characters. Chinese requires at least 4,000 Chinese characters for everyday language use, and up to 40,000 for full literacy. Japanese uses Chinese characters together with kana; ordinary writing requires about 2,000 Chinese characters, but more are needed for proper nouns. In Korean, the use of Chinese characters in daily life is declining, and they play a supplementary role for technical terms, proper nouns, and the like. Since the characters needed for these languages far exceed the 256 available in an 8-bit encoding, at least a 16-bit fixed-width character encoding or a variable-width character encoding is required, along with a special character set such as Unicode or GB18030.
Although CJK encodings share a common character set, each encoding was developed differently by country, so they are not compatible with each other. Encodings supporting Unicode have been attempted. Such encodings must support at least Chinese characters, Hangul, Pinyin, Bopomofo, and kana.
Types
CJK character encodings are as follows.
- Big5
- EUC-JP
- EUC-KR
- GB18030 (encoding proposed by the People's Republic of China)
- GB2312
- ISO 2022-JP
- Shift-JIS
The CJK character set uses a large part of Unicode, with CJK Unified Ideographs as its representative block. These languages can be written both horizontally and vertically, but they are usually treated as left-to-right languages.