What Is a Zero Byte File?

Byte is a unit of measurement used by computer information technology to measure storage capacity. A binary number string processed as a unit is a small unit of information. The most commonly used byte is an eight-bit byte, that is, it contains an eight-bit binary number.

Bytes are units of binary data. A byte is usually 8 bits long. However, some older computer architectures use different lengths. To avoid confusion, in most international literature, words are used instead of byte. In most computer systems, a byte is an 8-bit unit of data. Most computers use a byte to represent a character, number, or other character. A byte can also represent a series of binary bits. In some computer systems, 4 bytes represent a word, which is a unit of data that a computer can effectively process when executing instructions. Some language descriptions require 2 bytes to represent a character, which is called a double-byte character set. Some processors can handle double-byte or single-byte instructions. Bytes are often abbreviated as "B" and bits are often abbreviated as lowercase "b". The size of computer memory is usually expressed in bytes ^[1]

Byte data type (byte type) is stored in one byte (Byte), which can distinguish 256 numbers. The value range is 0 to 255. Byte is an unsigned type from 0-255, so it cannot represent negative numbers.

The effect is equivalent to unsigned char

typedef unsigned char BYTE

Define a new type BYTE, which is actually an unsigned char

In VC ++, the definition of byte data is included in the windows.h header file. To call byte, you need to add code #include <windows.h>

And in java, byte is a keyword

Indicates that an integer constant was declared to occupy one byte in the content

The value range is -128 ~ 127

word

In computers, a series of numbers that are processed or calculated as a whole is called a computer word, or a word for short. Words are usually divided into bytes (each byte is usually 8 bits). In memory, there is usually one word per cell, so each word is addressable. The length of a word is expressed in digits.

In computers and controllers of computers, they are usually transmitted in word units. The meaning of words appearing at different addresses is different. For example, the word sent to the controller is an instruction, and the word sent to the arithmetic unit is a number.

Word length

The number of bits contained in each word of a computer is called the word length. Depending on the computer, there are two types: fixed and variable. Fixed word length, that is, the word length is constant regardless of the situation; variable word length, within a certain range, its length is variable.

The calculated word length is the number of binary digits it can process at a time. ^[3] The rate at which a computer processes data is naturally related to the number of bits it can process at one time and the speed with which it performs operations. If one computer is twice as long as the other, even if both computers are the same speed, the former can do twice as much work as the latter in the same amount of time.

Generally, the word length of a large computer is 32-64 bits, a small computer is 12-32 bits, and a microcomputer is 4-16 bits. Word length is an important factor in computer performance.

In a microcomputer, how many bytes are usually used to represent the storage capacity of a memory.

For example, in a C ++ data type representation, usually char is 1 byte, int is 4 bytes, and double is 8 bytes.

The key to understanding encoding is to understand the concepts of characters and bytes accurately. These two concepts are easy to confuse, and we make a distinction here:

Examples of concept descriptions

Character A symbol used by people, a symbol in the abstract sense. '1', 'medium', 'a', '$', '' ...

A unit of data stored in a byte computer, an 8-bit binary number, is a very specific storage space. 0x01, 0x45, 0xFA ...

String

In memory, if a "character" exists in ANSI encoding, a character may be represented by one or more bytes, then we call this string an ANSI string or a multi-byte string. For example, "Chinese 123" (occupies 8 bytes, including a hidden \ 0).

character set

For ANSI encoding, there are different character sets (Charset). The same byte sequence represents different characters in different character sets. To correctly parse an ANSI string, the correct character set must be selected, otherwise it may cause so-called garbled characters. Different language versions of the operating system have a default character set. Without specifying a character set, the system uses this character set to parse ANSI strings. That is, if we open an ANSI text file (a text file containing only ANSI strings) saved by the Japanese operating system under the simplified Chinese version of Windows, we will see garbled characters. However, if we open this file with a text editor with code selection such as Visual Studio and select the correct character set, we will see it in its original state. Note: Traditional characters in the Simplified Chinese character set and traditional characters in the Traditional Chinese character set may not have the same encoding.

Each character set has a certain number, called a code page. The code page of Simplified Chinese (GB2312) is 936, and the code page of the system default character set is 0, which means that a suitable character set is selected according to the language setting of the system.

Unicode

Strings are in memory. If "characters" exist in a serial number in Unicode, then we call such strings Unicode strings or wide-byte strings. In Unicode, each character occupies two bytes. For example, "Chinese 123" (occupies 10 bytes). The difference between Unicode and ANSI is equivalent to the difference between "full-width" and "half-width" in the input method.

Because different ANSI encodings have different standards (different character sets), we must know which character set it uses for a given multibyte string in order to know that it contains Which "characters". For a Unicode string, the "character" content it represents is always the same regardless of the environment. Unicode has a unified standard, which defines the encoding of most characters in the world, so that Latin, numbers, simplified Chinese, traditional Chinese, and Japanese can be saved in the same encoding.