Member variables in classes are called fields. Fields are used to store the internal data for a class.

  • It is recommended to always declare all fields in the private section of a class, unless the class is very simple and mainly used to group a set of variables. As an illustration, compare the Point example with the Texture example.
  • By convention, field names start with a lowercase “f”, such as fMyData. This allows you to easily see the difference between fields and local variables or arguments.
  • Fields can be of any type, just like variables. They can be arrays, dynamic arrays, or object references. The type of a field can even be the type of the class that it is declared in, so you can create recursive data structures like a tree or a linked list.
  • Unlike formula variables or local function variables, all fields of a class are automatically initialized to 0. Use a constructor to initialize them explicitly.

Here is a very simple example of a linked list node that refers to itself:

  class Node {    Node next    int data  }    

Usage example:

  Node head = new Node = 2 = new Node = 3  Node n = head  while n    print(  ; Prints 2 and 3    n =  endwhile    

Note that it is not necessary to initialize the next reference when creating a node, because it is automatically initialized to 0, the null reference.

Next: Methods

See Also