Introduction to Class Parameters

A class parameter defines a special constant value available to all objects of a given class. When you create a class definition (or at any point before compilation), you can set the values for its class parameters. By default, the value of each parameter is the null string, but you can specify a non-null value as part of the parameter definition. At compile-time, the value of the parameter is established for all instances of a class. With rare exceptions, this value cannot be altered at runtime.

Class parameters are typically used for the following purposes:

To customize the behavior of the various data type classes (such as providing validation information).
To define user-specific information about a class definition. A class parameter is simply an arbitrary name-value pair; you can use it to store any information you like about a class.
To define a class-specific constant value.
To provide parameterized values for method generator methods to use. A method generator is a special type of method whose implementation is actually a short program that is run at compile-time in order to generate the actual runtime code for the method. Many method generators use class parameters.

Defining Class Parameters