1. A category can be declared if class source code does not exist. 2. Category will be available to all instances of original class and subclass. 3. During runtime, there's no difference between a method added by a category and method that is implemented by the original class.
1. A category can be declared if class source code does not exist.
2. Category will be available to all instances of original class and subclass.
3. During runtime, there's no difference between a method added by a category and method that is implemented by the original class.