Difference between categories and inheritance??

[prudhvi]

hi everyone,can anyone tell me the difference between categories and inheritance..categories are used to add the functionality to the existing class,but we can also do that using inheritance..then what is the use of categories..i searched this in google..but not got a satisfied answer..Thanks in advance..

[Domele]

Subclassing will create a new class where the method exists. With categories, you can add a method to an existing class and use that class.

[assistman]

Originally Posted by prudhvi

hi everyone,can anyone tell me the difference between categories and inheritance..categories are used to add the functionality to the existing class,but we can also do that using inheritance..then what is the use of categories..i searched this in google..but not got a satisfied answer..Thanks in advance..

You use category to change the current class. All instances of that class you create after adding a category would implement the category method(s). So you actually lose access to the "old" class.