MATLAB Object-Oriented Programming

Object Precedence in Method Invocation

In this section...

“Object Precedence” on page 9-47

“Defining Precedence” on page 9-48

Object Precedence

Establishing an object precedence enables MATLAB to determine which of possibly many

versions of an operator or function to call in a given situation.

For example, consider the expression

objectA + objectB

Ordinarily, objects have equal precedence and the method associated with the leftmost

object is called. However, there are two exceptions:

• Classes defined with the classdef syntax have precedence over these MATLAB
  classes:

double, single, int64, uint64, int32, uint32, int16, uint16, int8, uint8,

char, string, logical, cell, struct, and function_handle.

• Classes defined with the classdef syntax can specify their relative precedence with
  respect to other classes using the InferiorClasses attribute.

Consider the example in “Representing Polynomials with Classes” on page 19-2. The

DocPolynom class defines a plus method that enables the addition of DocPolynom

objects. Given the object p:

p = DocPolynom([1 0 -2 -5])

p =

x^3-2*x-5

the expression:

1 + p

ans =

x^3-2*x-4

Object Precedence in Method Invocation