MATLAB Object-Oriented Programming

Operator Overloading

In this section...

“Why Overload Operators” on page 17-47

“How to Define Operators” on page 17-47

“Sample Implementation — Addable Objects” on page 17-48

“MATLAB Operators and Associated Functions” on page 17-50

Why Overload Operators

By implementing operators that are appropriate for your class, you can integrate objects

of your class into the MATLAB language. For example, objects that contain numeric data

can define arithmetic operations like +, *, - so that you can use these objects in

arithmetic expressions. By implementing relational operators, you can use objects in

conditional statements, like switch and if statements.

How to Define Operators

You can implement MATLAB operators to work with objects of your class. To implement

operators, define the associated class methods.

Each operator has an associated function (e.g., the + operator has an associated plus.m

function). You can implement any operator by creating a class method with the

appropriate name. This method can perform whatever steps are appropriate for the

operation being implemented.

For a list of operators and associated function names, see “MATLAB Operators and

Associated Functions” on page 17-50.

Object Precedence in Operations

User-defined classes have a higher precedence than built-in classes. For example,

suppose q is an object of class double and p is a user-defined class. Both of these

expressions generate a call to the plus method in the user-define class, if it exists:

q + p

p + q

Operator Overloading