The following table shows the keywords for built-in C# types, which are aliases of predefined types in the System namespace.
| C# Type | .NET Framework Type | 
|---|---|
| System.Boolean | |
| System.Byte | |
| System.SByte | |
| System.Char | |
| System.Decimal | |
| System.Double | |
| System.Single | |
| System.Int32 | |
| System.UInt32 | |
| System.Int64 | |
| System.UInt64 | |
| System.Object | |
| System.Int16 | |
| System.UInt16 | |
| System.String | 
Remarks
All of the types in the table, except object and string, are referred to as simple types.
The C# type keywords and their aliases are interchangeable. For example, you can declare an integer variable by using either of the following declarations:
int x = 123;
System.Int32 x = 123;
To display the actual type for any C# type, use the system method GetType(). For example, the following statement displays the system alias that represents the type of myVariable:
Console.WriteLine(myVariable.GetType());
You can also use the typeof operator.
See Also
Reference
Concepts
Other Resources
Default Values Table (C# Reference)