Understanding Common Type System in .Net Framework

Understanding Common Type System in .Net Framework

As .Net Framework is language independent and support over 20 different programming languages, many programmers will write data types in their own programming language.

For example, an integer variable in C# is written as int, whereas in Visual Basic it is written as integer. Therefore in .Net Framework you have single class called System.Int32 to interpret these variables. Similarly, for the ArrayList data type .Net Framework has a common type called System.Collections.ArrayList. In .Net Framework, System.Object is the common base type from where all the other types are derived.

This system is called Common Type System. The types in .NET Framework are the base on which .NET applications, components, and controls are built. Common Type System in .Net Framework defines how data types are going to be declared and managed in runtime. The Common Type System performs the following functions:

• Automatically adapts itself in a framework that enables integration of multiple languages, type safety, and high performance code execution.
• Provides an object-oriented model.
• Standardizes the conventions that all the languages must follow.
• Invokes security checks.
• Encapsulates data structures.

There are two general types of categories in .Net Framework that Common Type System support. They are value types and reference types. Value types contain data and are user-defined or built-in. they are placed in a stack or in order in a structure. Reference types store a reference of the value’s memory address. They are allocated in a heap structure. You can determine the type of a reference by the values of self-describing types. Reference types can be categorized into self-describing types, pointer types, or interface types.

There are many other types that can be defined under Value types and Reference types. In .Net Framework, the System namespace is the root for all the data types. This namespace consists of classes such as Object, Byte, String, and Int32 that represents base data types. These base data types are used by all applications. During runtime a type name can be classified into two: the assembly name and the type’s name within the assembly. The runtime in .Net Framework uses assemblies to find and load types.

To access online version of the above article, go to http://www.dotnet-guide.com/commontype.html