What is a character encoding and what are the characteristics of each of them

The standardization of information coding is based on the needs of information management to express things (concepts) or their characteristics, and the principles and methods of their identification are published and managed in a standard (specification) manner. This work is a basic work, with a wide and far-reaching impact and great difficulty in promoting, and has the following four basic characteristics.

1.Information coding standardization is essentially a high-level standardization.

The standardization of information classification and coding solves the problem of standardization at the data level, so it should be combined with the overall project of enterprise informatization for unified planning and deployment, so as to achieve broader coordination and unification at the enterprise level, and pave the way for information integration and sharing and resource integration and optimization.

2.The standardization of information coding involves multi-discipline and multi-disciplinary.

Information classification and coding standardization involves design, manufacturing, management, computer, standards and other disciplines and professions, the disciplines and specialties intersect with each other, mutual penetration, so a coding method often needs computer technicians, engineering and technical personnel and standardization personnel to jointly study and determine, it should not only reflect the mode of information organization and management, but also require scientific and practical, the need for all relevant units, departments and professionals to work together vigorously to achieve.

3.The standardization of information coding has the characteristics of the whole process and all aspects.

The scope of information coding standardization work of manufacturing enterprises covers various manufacturing materials from products, parts and components to raw materials, equipment, tooling, etc., from market research (project demonstration of military products) to product design, manufacturing, assembly, testing, finalization, use and scrapping of the whole process, the front end extends to the first business, and the back end extends to customers, with the whole process and all-round significant characteristics.

4.The standardization of information coding is aimed at the pursuit of unification (uniqueness).

In practice, when classifying and coding specific things (or concepts), there are often a variety of methods to choose from, each of which has its own advantages and disadvantages, when it is difficult to judge which method is the best choice, the pursuit of unity (unique) becomes the main purpose, at this time, enterprises should determine a method as soon as possible, set up a benchmark, and form a standard for unified release and use.

For the standardization of information coding, it is a key step to clarify which information objects need to be encoded, collect and analyze the generation and use requirements of the first generation, etc., and this paper implements three ways from the enterprise business, the whole life cycle of products and the information system.

Character encoding generally refers to computer languages, i.e. 0s and 1s, because in computer languages, there are only 0s and 1s.

The national standard code is the GB national standard code: one of the Chinese internal codes, representing Chinese simplified characters, widely used in Chinese mainland, with all its influence, and the use is gradually becoming popular. "Chinese character code for national standard information exchange" (GB2312-80 standard), referred to as the national standard code.

The international code is a two-byte code that uses two seven-digit binary numbers to encode a Chinese character.

ASCII Code: The American (national) information exchange standard (code), a scheme that uses 7 or 8 binary bits for encoding, and can assign (or specify) numeric values to up to 256 characters, including letters, numbers, punctuation marks, control characters, and other symbols. The ASCII code is divided into two sets:

The 128-character standard ASCII code and the additional 128-character augmentation and ASCII code.

The BCD code is BCD**. Binary-coded decimal (abbreviated as BCD), known as BCD code or binary decimal **, also known as binary decimal number. It is a form of binary numeric encoding, with binary encoded decimal**.

This form of encoding uses four bits to store a decimal digit, allowing for quick and easy conversion between binary and decimal systems. This coding technique is most commonly used in the design of accounting systems, which often require accurate calculations on long strings of numbers. Compared with the general floating-point notation, the BCD code can not only save the accuracy of the value, but also avoid the time spent by the computer in floating-point arithmetic.

In addition, BCD codes are commonly used for other calculations that require high accuracy.

Commonly used BCD codes.

Decimal number: 8421 codes, 5421 codes, 2421 codes, 3 more codes, 3 cycle codes.

Generally, the last few pages of professional textbooks will have national standard codes, ASCII codes, and BCD codes.

EBCDIC code, I didn't learn it, so there's no way to help you, sorry.

Hope the above works for you though.

Classification of Chinese character input code: Chinese character is a kind of pinyin, pictographic and ideographic characters, which itself has a very rich connotation of sound, shape and meaning. After many years of painstaking research by many Chinese, a wide variety of Chinese character input codes have been formed, and so far, hundreds of Chinese character input code coding schemes have come out, of which dozens have been widely used.

According to the different materials of the encoding elements entered by Chinese characters

ASCII code. The most widely used Western character set and its encoding are the ASCII character set and ASCII code (ASCII is an abbreviation for American Standard Code for Information Interchange), which has also been approved as an international standard by the International Organization for Standardization (ISO).

ISO2022 standard.

Specifies a uniform approach to expanding the ASCII character set to 8 digits while maintaining compatibility with ISO646. ISO has successively developed a number of extended ASCII character sets for different regions, each of which can be extended to 128 characters, and these extended characters are encoded in 8 digits with a high score of 1 (i.e., the decimal number 128 255), which is called an extended ASCII code.

By understanding the storage encoding of characters, many problems caused by encoding mismatch can be solved, such as web page garbled and email garbled, and this article briefly clarifies ASCII encoding, EBCDIC encoding, GB2312 encoding, UTF-8 encoding, and Base64 encoding.

Chinese character codes are mainly divided into four categories: Chinese character input code, Chinese character exchange code, Chinese character internal code and Chinese character glyph code.

1) The external code of the Chinese character.

The external code of Chinese characters is referred to as the outer code, also known as the input code, which is a set of keyboard symbols for the input of Chinese characters. Different input methods are used, and the external code of the same kanji is different. Users should choose easy to remember, simple to operate, less bit code, less heavy code and fast input speed.

2) The internal code of the Chinese character.

The internal code of Chinese characters is also known as the internal code of Chinese characters or the internal code of Chinese characters. After the machine receives the outer code, it should be converted into the inner code for storage, calculation and transmission. The internal code of a Chinese character is represented by two bytes.

In order to distinguish it from Western symbols, the highest digit of the inner code is set to "1". The internal code is usually represented by the physical location of the Chinese character in the garage, which can be the serial number of the Chinese character in the font or the storage location in the font.

3) Chinese character exchange code.

When exchanging information between computers, the Chinese characters ** that are required to be transmitted conform to the exchange code standards stipulated by the state, that is, to comply with the GB2312-80 Chinese character code set for information exchange, also known as the national standard code. The national standard code collects 7,445 graphic characters, including 6,763 Chinese characters and 709 symbols.

4) Chinese character glyph code.

When displaying or printing Chinese characters, there is also a glyph code, also known as an output code. The glyph of Chinese characters refers to the size and shape of the original lead typesetting Chinese characters, and in the computer refers to the dot matrix that makes up the Chinese characters.

Although there are many variations of Chinese characters with different strokes, they are all square characters and the same size, and they can all be written in the same square. Think of a square as a matrix of n rows and n columns, with a total of m n points, which is called the Chinese dot matrix. For example, the Chinese characters of 16 and 16 dots have a total of 256 dots.

Chinese character encoding. Chinese character encoding is a kind of Chinese character encoding designed for easy input into the computer. Since the existing input keyboard of the electronic computer is fully compatible with the English typewriter keyboard.

Therefore, how to input non-Latin scripts (including Chinese characters) has been the subject of research for many years.

The Chinese character information processing system generally includes encoding, input, storage, output, and transmission. Coding is key. Without solving this problem, Chinese characters cannot enter the computer.

The three ways in which Chinese characters can enter a computer are:

Input through speech recognition: The computer uses the "auditory organs" that people equip it with to automatically identify Chinese phonetic elements, find different Chinese characters from different syllables, or judge different Chinese characters from the same syllable.

Input through Chinese character encoding: According to a certain coding method, Chinese characters are input into the computer by a person with the help of an input device.

Machine automatic recognition of Chinese characters and Chinese speech recognition are being studied at home and abroad, although a lot of progress has been made, but due to the difficulty, it is expected that it will take a considerable period of time to be solved. At this stage, it is more realistic to make Chinese characters into the computer through the Chinese character encoding method.

Encoding is a computer programming language that is the process by which information is converted from one form or format to another. Words, numbers, or other objects are usually digitalized by a predetermined method, or information and data are converted into prescribed electrical pulse signals. Encoded in an electronic computer.

It is widely used in television, remote control and communication.

Encoding is the conversion of analog information into a bitstream according to a certain protocol or format.

process. In computer hardware, coding is the process of converting information into encoded values (typically numbers) on a subject or unit for data storage, management, and analysis purposes. In software, coding means that logic is used to execute a program in a specific language such as C or C++.

In cryptography rushed away.

, encoding refers to the act of writing in a code or password.

Convert data into code or encoded characters and translate them into the original data form. It is the process of writing instructions on a computer, a part of programming. In automatic map mapping, the process of using numbers and letters to represent the content of the map according to certain rules, through coding, enables the computer to identify the geographical elements of the map.

N-bit binary numbers.

It can be combined into 2 different pieces of information to the nth power, and a specific code group is specified for each message, which is also called encoding.

The four main encodings of Chinese characters are: outer code, exchange code, in-machine code and glyph code.

1. Outer code. A codecode is a set of keyboard symbols used to input Chinese characters into a computer. The input code used by Changzheng empty includes pinyin code, Wubi font code, natural code, phenographic code, cognitive code, area code and telegram code.

2. Exchange code.

The exchange code computer processes the information internally, and the binary ** table is used, and the information exchange code needs to be used.

3. In-machine code.

According to the provisions of the national standard code, each Chinese character has a certain two-disadvantage Hu base system**, and the internal code is used in the internal Chinese characters in the microcomputer, and the internal code is also used in the recording of Chinese characters on the disk.

4. Glyph code.

The glyph code is the output code of the Chinese characters, and the output of the Chinese characters is all in a graphic way, no matter how many strokes the Chinese characters have, each Chinese character can be written in a square of the same size.

Advantages and disadvantages of Chinese character encoding

1. Support Chinese characters: Chinese character encoding can directly represent Chinese characters without the use of escape characters or other methods.

2. Good compatibility: Chinese character coding has good compatibility between different computer platforms, which is convenient for transmitting and sharing text information between different systems.

3. Occupy a large space: Chinese character coding needs to use more code points to represent Chinese characters, which takes up a large space.

4. Low efficiency: The search and comparison efficiency of Chinese character coding is low, which has a certain impact on the performance of large-scale text processing systems.

An object in a collection of characters represented by a menist is called a character encoding, so that the text can be stored in a computer and passed over a communication network. Common examples include encoding the Latin alphabet into Morse code and ASCII, where ASCII numbers letters, numbers, and other symbols and represents the integer in 7-bit binary.

In the early days of computer technology, character sets such as ASCII and EBCDIC gradually became the standard. But the limitations of these character sets quickly became apparent, and many ways were developed to extend them.

The requirement to support a writing system, including the East Asian CJK character family, supports a larger number of characters, and requires a systematic rather than ad hoc method to encode these characters.

Encoding. The characters are encoded with one byte and two bytes, one in the 00 7f range, and are consistent with ASCII, which technically contains 96 characters and 32 control symbols.

In the next double byte, the first byte is the first double byte. In general, the range of the first byte is 81 fe, some areas of the second byte are 40 7e, and the other fields are 80 fe.

For the above content, please refer to Encyclopedia - Character Encoding.