Fields
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 head.data = 2 head.next = new Node head.next.data = 3 Node n = head while n print(n.data) ; Prints 2 and 3 n = n.next 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
Classes
Variables