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Importing Classes

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Related Information Syntax for Importing Classes

Related Information

See Scoping Classes with Packages for information about packages.

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Syntax for Importing Classes

You can import classes into a function to simplify access to class members. For example, suppose there is a package that contains a number of classes, but you need to use only one of these classes in your function, or perhaps even just a static method from that class. You can use the import command as follows:

function myFunc
   import pkg.cls1 
   obj = cls1(arg,...); % call cls1 constructor
   obj.Prop = cls1.StaticMethod(arg,...); % call cls1 static method
end

Note that you do not need to reference the package name (pkg) once you have imported the class (cls1). You can also import all classes in a package using the syntax pkg.*, where * indicates all classes in the package. For example,

function myFunc
   import pkg.* 
   obj1 = cls1(arg,...); % call pkg.cls1 constructor
   obj2 = cls2(arg,...); % call pkg.cls2 constructor
   a = pkgFunction();  % call package function named pkgFunction
end

Importing Package Functions

You can use import with package functions:

function myFunc
   import pkg.pkfcn 
   pkfcn(arg,...); % call imported package function
end

Package Function and Class Method Name Conflict

Suppose you have the following directory organization:

+pkg/timedata.m % package function
+pkg/@myclass/myclass.m % class definition file
+pkg/@myclass/timedata.m % class method

Now import the package and call timedata on an instance of myclass:

import pkg.*
myobj = pkg.myclass;
timedata(myobj)

A call to timedata finds the package function, not the class method because MATLAB applies the import and finds pkg.timedata first. You should not use a package in cases where you have name conflicts and plan to import the package.

Clearing Import List

You can not clear the import list from a function workspace. To clear the base workspace only, use:

clear import

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Scoping Classes with Packages

Referring to Constant Values

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