Encoding

Encoding

A class in the System.Text namespace that represents character encodings and provides operations for converting between Unicode characters and encoded byte sequences. Domain: C# → .NET → System.Text → Character Encoding

Encoding.UTF8

Gets a UTF-8 encoding, which represents Unicode characters using a variable number of bytes.

Encoding.Unicode

Gets a UTF-16 little-endian encoding, where text is represented using 16-bit code units.

Encoding.BigEndianUnicode

Gets a UTF-16 big-endian encoding, which stores the most significant byte of each 16-bit code unit first.

Encoding.UTF32

Gets a UTF-32 little-endian encoding, which represents Unicode code points using 32-bit code units.

Encoding.ASCII

Gets an ASCII encoding, which represents the 128 standard ASCII characters.

Encoding.Latin1

Gets the Latin-1 encoding, which directly represents the first 256 Unicode code points using one byte each.

byte[] bytes = Encoding.UTF8.GetBytes(text);

Converts the characters in text into a byte array using UTF-8 encoding.

string text = Encoding.UTF8.GetString(bytes);

Decodes a UTF-8 encoded byte array into a C# string.

int byteCount = Encoding.UTF8.GetByteCount(text);

Calculates how many bytes are required to encode the specified text using UTF-8.

int charCount = Encoding.UTF8.GetCharCount(bytes);

Calculates how many UTF-16 char values will result from decoding the specified UTF-8 bytes.

char[] chars = Encoding.UTF8.GetChars(bytes);

Decodes a UTF-8 byte array into an array of characters.

int maxBytes = Encoding.UTF8.GetMaxByteCount(charCount);

Calculates the maximum possible number of bytes that may be required to encode a specified number of characters.

int maxChars = Encoding.UTF8.GetMaxCharCount(byteCount);

Calculates the maximum possible number of characters that may result from decoding a specified number of bytes.

Encoding encoding = Encoding.GetEncoding("utf-8");

Gets an Encoding object for an encoding specified by name.

Encoding.Default

Gets the default encoding for the current .NET environment.

Unrepresentable Character

A character that cannot be represented by a particular character encoding, such as many Unicode characters when using ASCII.

Encoding encoding = Encoding.GetEncoding("ASCII", EncoderFallback.ExceptionFallback, DecoderFallback.ExceptionFallback);

Configures the encoding to throw an exception when a character cannot be represented instead of silently replacing it.

Encoder

A stateful object that converts characters into bytes while preserving conversion state when text is processed in multiple chunks.

Decoder

A stateful object that converts encoded bytes into characters while preserving conversion state when byte data is processed in multiple chunks.

Encoding Preamble

A sequence of bytes that may appear at the beginning of encoded data to provide information about its character encoding.

byte[] preamble = encoding.GetPreamble();

Returns the sequence of bytes representing the preamble associated with the specified encoding.

read-only sequence

Encoding Preamble Property provides the preamble associated with an encoding as a ________________ of bytes. It can be used to inspect whether that particular encoding supplies a preamble.

Byte Order Mark (BOM)

A byte sequence that may appear at the beginning of Unicode-encoded text to identify its encoding and, where relevant, its byte order.

Unicode Code Point

A numerical value assigned to a Unicode character or text element, conventionally written in a form such as U+0041 for A.

UTF-16 Code Unit

A 16-bit unit used by UTF-16 to represent Unicode text; some Unicode code points require one code unit, while others require two.

Surrogate Pair

Two UTF-16 code units—a high surrogate followed by a low surrogate—used together to represent a Unicode code point outside the Basic Multilingual Plane.

char

A ____ in C# represents one UTF-16 code unit, not necessarily one complete Unicode character. Therefore, some Unicode characters require 2 of these values.