MATLAB Object-Oriented Programming

end as Object Index

In this section...

“Define end Indexing for an Object” on page 17-35

“The end Method” on page 17-36

Define end Indexing for an Object

When you use end in an object indexing expression, such as A(4:end), the end function

returns the index value corresponding to the last element in that dimension.

Classes can overload the end function to implement specialized behavior. If your class

defines an end method, MATLAB calls that method to determine how to interpret the

expression.

The end method has the calling syntax:

ind = end(A,k,n)

The arguments are described as follows:

• A is the object


• k is the index in the expression using the end syntax


• n is the total number of indices in the expression


• ind is the index value to use in the expression

For example, consider the 3-by-5 array A. When MATLAB encounters the expression:

A(end-1,:)

MATLAB calls the end method defined for the object A using the arguments:

ind = end(A,1,2)

These arguments mean that the end statement occurs in the first index and there are two

indices. The end class method returns the index value for the last element of the first

dimension (from which 1 is subtracted in this case). The original expression is evaluated

as:

A(3-1,:)

end as Object Index