MATLAB Object-Oriented Programming

function n = numArgumentsFromSubscript(obj,s,indexingContext)

...

end

Input Argument Description

obj Object whose subsref or subsasgn method is called

s Indexing structure that contains the indexing type and indices used

in the operation

indexingContex

t

Context in which the indexing operation occurs: indexed reference

used as a statement, index reference used as a function argument,

and indexed assignment

MATLAB uses the value returned by numArgumentsFromSubscript for indexed

reference and assignment. Determine the context in which the indexing operation

executes by testing the value of indexingContext in your implementation of

numArgumentsFromSubscript. For example, test for any or all the possible indexing

contexts.

function n = numArgumentsFromSubscript(obj,~,indexingContext)

switch indexingContext

case matlab.mixin.util.IndexingContext.Statement

n = ...; % nargout for indexed reference used as statement

case matlab.mixin.util.IndexingContext.Expression

n = ...; % nargout for indexed reference used as function argument

case matlab.mixin.util.IndexingContext.Assignment

n = ...; % nargin for indexed assignment

end

end

For more information and examples, see numArgumentsFromSubscript.

NoteFor MATLAB version R2015b and later releases, overload

numArgumentsFromSubscript instead of numel to customize indexing for your class.

See Also

More About

• “Number of Arguments for subsref and subsasgn” on page 17-6


• “Use of size and numel with Classes” on page 12-77

17 Specialize Object Behavior