CSE 110 Final Questions and Correct Answer

Test cases have a workflow section where user entry is exact and steps are included to demonstrate the desired functionality. ~~True Design Principle: Depend upon ____ classes. Do not depend upon ____ classes. ~~abstraction, concrete A null object is useful when you want to eliminate the responsibility from the client for handling null pointers. ~~True Inheritance relationship ~~Is-a Composition relationship ~~Has-a Interface relationship ~~Implements Observer Pattern ~~Describes one to many dependencies (one subject to many observers), when the one changes state the many are notified. "subscribe". Singleon Pattern ~~A class has only one instance and a global point of access to it. Command Pattern ~~Encapsulates a request as an object, thereby letting you parameterize other objects with different requests, queue or log requests, and support undoable operations. Adapter Pattern ~~Converts the interface of a class into another interface clients expect. Lets classes work together that couldn't otherwise because of incompatible interfaces. Facade Pattern ~~Provides a unified interface to a set of interfaces in a subsystem. Defines a higherlevel interface that makes the subsystem easier to use Template Method ~~Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Lets subclasses redefine certain steps of an algorithm without changing the algorithm's structure. Iterator Pattern ~~Provide a way to access the elements of an aggregate object sequentially without exposing its underlying representation. Composite Pattern ~~Compose objects into tree structures to represent part-whole hierarchies. Lets clients treat individual objects and compositions of objects uniformly. State Pattern ~~Allow an object to alter its behavior when its internal state changes. The object will appear to change its class. Proxy Pattern ~~Provides a surrogate or placeholder for another object to control access to it. Factory Pattern ~~Defines an interface for creating an object but lets subclasses decide which class to instantiate. Les a class defer instantiation to the subclasses