MATLAB Object-Oriented Programming

Concatenating Objects of Different Classes

In this section...

“Basic Knowledge” on page 10-18

“MATLAB Concatenation Rules” on page 10-18

“Concatenating Objects” on page 10-19

“Calling the Dominant-Class Constructor” on page 10-19

“Converter Methods” on page 10-21

Basic Knowledge

The material presented in this section builds on an understanding of the information

presented in the following sections.

• “Construct Object Arrays” on page 10-2


• “Valid Combinations of Unlike Classes”

MATLAB Concatenation Rules

MATLAB follows these rules for concatenating objects:

• MATLAB always attempts to convert all objects to the dominant class.


• User-defined classes take precedence over built-in classes like double.


• If there is no defined dominance relationship between any two objects, then the left-
  most object dominates (see “Class Precedence” on page 6-23).

When converting to a dominant class during concatenation or subscripted assignment,

MATLAB searches the non-dominant class for a conversion method that is the same name

as the dominant class. If such a conversion method exists, MATLAB calls it. If a

conversion method does not exist, MATLAB calls the dominant class constructor on the

non-dominant object.

It is possible for the dominant class to define horzcat, vertcat, or cat methods that

modify the default concatenation process.

10 Object Arrays