System.Text Namespace

Provides fundamental classes that represent characters, strings, and the various encodings that strings use to be represented in memory and in files.

Classes

Encoding Represents a character encoding.
Decoder Decodes a sequence of byte arrays into a sequence of characters.
Encoder Encodes a sequence of characters into a sequence of byte arrays.
StringBuilder Represents a mutable sequence of characters.
NormalizationForm Specifies the Unicode normalization form to use.

Abstract Classes

Encoding Represents a character encoding.
Decoder Decodes a sequence of byte arrays into a sequence of characters.
Encoder Encodes a sequence of characters into a sequence of byte arrays.

Interfaces

IDecoder Provides functionality for decoding character data.
IEncoder Provides functionality for encoding character data.

Commonly Used Classes

The System.Text namespace includes several important classes for text manipulation:

StringBuilder

The StringBuilder class is used to create mutable strings. It's more efficient than repeatedly concatenating strings in a loop.


using System.Text;

StringBuilder sb = new StringBuilder();
sb.Append("Hello");
sb.Append(", ");
sb.Append("World!");
string result = sb.ToString();
Console.WriteLine(result); // Output: Hello, World!

Encoding

The Encoding class and its derived classes (e.g., UTF8Encoding, ASCIIEncoding) are used to convert strings into byte arrays and vice versa, supporting various character encodings.


using System.Text;

string text = "Hello, .NET!";
byte[] utf8Bytes = Encoding.UTF8.GetBytes(text);
string decodedText = Encoding.UTF8.GetString(utf8Bytes);
Console.WriteLine(decodedText); // Output: Hello, .NET!