4.1 Core Types

The core types are contained in the System namespace. This namespace is the heart of the FCL and contains classes, interfaces, and attributes that all other types depend on. The root of the FCL is the type Object, from which all other .NET types derive. Other fundamental types are ValueType (the base type for structs), Enum (the base type for enums), Convert (used to convert between base types), Exception (the base type for all exceptions), and the boxed versions of the predefined value types. Interfaces used throughout the FCL—such as ICloneable, IComparable, IFormattable, and IConvertible—are defined here (see Section 3.3 in Chapter 3).Extended types such as DateTime, TimeSpan, and DBNull are also available. Other classes include support for delegates (see Section 2.13 in Chapter 2), basic math operations (see Section 3.2 in Chapter 3), attributes (see Section 2.16 in Chapter 2), and exception handling (see Section 2.15 in Chapter 2).

For more information, see the System namespace.