Member functions in classes are called methods. Methods typically perform operations on the fields of a class. Methods are declared just like functions in a formula.

Methods always operate on an instance of the class (except static methods). The instance is returned by the reserved this reference. Here is an example:

  class Data {    int x    func printMe(Printer p)      p.printData(this)    endfunc  }    class Printer {  $define debug    func printData(Data d)      print(d.x)    endfunc  }    

If you call a method on an object reference, the this reference inside the method will return the object reference that it was called on.

  Data d = new Data  d.x = 12  d.printMe(new Printer)  ; Prints 12    

In this code fragment, the this reference in Data.printMe() will return the d reference, which is then passed to the Printer object.

Note that objects are always passed to functions and methods by reference (see also Function arguments). For example, the Printer.printData() method could change the x value of the Data object that it receives. If you include the & symbol with the function argument (as you would do for normal by-reference argument passing), this lets the function modify the actual object reference which is often not needed.

Next: Overriding

See Also
Static methods