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subsref

Redefine subscripted reference for objects

Syntax

B = subsref(A,S)

Description

B = subsref(A,S) is called by MATLAB® for the syntax A(i), A{i}, or A.i when A is an object.

MATLAB uses the built-in subsref function to interpret indexed references to objects. To modify the indexed reference behavior of objects, overload subsref in the class.

Input Arguments

A

Object used in indexing operation

S

Structure with two fields, type and subs. For compound indexing expressions, S is an array of structures, one for each level of indexing.

  • type is a char vector containing '()', '{}', or '.', indicating the type of indexing used.

  • subs is a cell array or character array containing the actual subscripts.

Output Arguments

B

Result of the indexed expression.

Examples

See how MATLAB calls subsref for the expression:

A(1:2,:)

The syntax A(1:2,:) calls B = subsref(A,S) where S is a 1-by-1 structure with S.type='()' and S.subs={1:2,':'}. The color character ':' indicates a colon used as a subscript.

See how MATLAB calls subsref for the expression:

A{1:2}

The syntax A{1:2} calls B = subsref(A,S) where S.type='{}' and S.subs={[1 2]}.

See how MATLAB calls subsref for the expression:

A.field

The syntax A.field calls B = subsref(A,S) where S.type='.' and S.subs='field'.

See how MATLAB calls subsref for the expression:

A(1,2).name(3:5)

Simple calls combine in a straightforward way for more complicated indexing expressions. In such cases, length(S) is the number of subscript levels. For instance, A(1,2).name(3:5) calls subsref(A,S) where S is a 3-by-1 structure array with the following values:

S(1).type='()'S(2).type='.'S(3).type='()'
S(1).subs={1,2}S(2).subs='name'S(3).subs={[3 4 5]}

Related Examples

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Tips

Within the subsref method defined by a class, MATLAB calls the built-in subsref. Calling the built-in enables you to use the default indexing behavior when defining specialized indexing. For more information, see Built-In subsref and subsasgn Called in Methods.

Introduced before R2006a

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