MATLAB Object-Oriented Programming

For example, suppose classA defines classB as inferior and suppose that both classes

define a method called combine.

Calling the method with an object of classB and classA:

combine(B,A)

actually calls the combine method of classA because A is the dominant argument.

Dot Notation vs. Function Notation

MATLAB classes support both function and dot notation syntax for calling methods. For

example, if setColor is a method of the class of object X, then calling setColor with

function notation would be:

X = setColor(X,'red');

The equivalent method call using dot notation is:

X = X.setColor('red')

However, in certain cases, the results for dot notation can differ with respect to how

MATLAB dispatching works:

• If there is an overloaded subsref, it is invoked whenever using dot notation. That is,
  the statement is first tested to see if it is subscripted assignment.


• If there is no overloaded subsref, then setColor must be a method of X. An
  ordinary function or a class constructor is never called using this notation.


• Only the argument X (to the left of the dot) is used for dispatching. No other
  arguments, even if dominant, are considered. Therefore dot notation can call only
  methods of X; methods of other argument are never called.

Case Where Result Is Different

Here is an example of a case where dot and function notation can give different results.

Suppose that you have the following classes:

• classA defines a method called methodA that requires an object of classB as one of
  its arguments


• classB defines classA as inferior to classB

9 Methods — Defining Class Operations