Programming and Data Types

Identifying Objects Outside the Class Directory

The class and isa functions used in constructor methods can also be used outside of the class directory. The expression

isa(a,'class_name');

checks whether a is an object of the specified class. For example, if p is a polynom object, each of the following expressions is true.

isa(pi,'double');
isa('hello','char');
isa(p,'polynom');

Outside of the class directory, the class function takes only one argument (it is only within the constructor that class can have more than one argument).

The expression

class(a);

returns a string containing the class name of a. For example,

class(pi), 
class('hello'), 
class(p)

return

'double', 
'char', 
'polynom'

Use the whos function to see what objects are in the MATLAB workspace.

whos

  Name      Size         Bytes  Class
  p         1x1          156 polynom object

The Class Constructor Method

The display Method