Summary

--- primaryColor: '#512888' secondaryColor: '#cccccc' textColor: black shuffleQuestions: true shuffleAnswers: true locale: en --- # Polymorphism **Polymorphism** is best described by what literal meaning? 1. [X] Many forms 1. [ ] Type shift 1. [ ] From many, one 1. [ ] Change into # Type A **type** is described in this chapter as giving what information about a variable? 1. [X] How it is represented and what operations can be performed on it 1. [ ] Whether it can be accessed by other objects 1. [ ] The location in the code where it is first created 1. [ ] Whether it is abstract or inheritable # User-Defined Types Which construct from object-oriented programming best represents a **user-defined type**? 1. [X] Class 1. [ ] Attribute 1. [ ] Method 1. [ ] Exception # Static Typing A **statically-typed** language has what property? 1. [X] The data type of a variable type is set when it is declared 1. [ ] The data type of a variable depends on what it contains 1. [ ] The data type of a variable can always be determined 1. [ ] The data type of a variable cannot always be determined # Dynamic Typing A **dynamically-typed** language has what property? 1. [ ] The data type of a variable type is set when it is declared 1. [X] The data type of a variable depends on what it contains 1. [ ] The data type of a variable can always be determined 1. [ ] The data type of a variable cannot always be determined # Message Passing In object-oriented programming, we can think of **message passing** as another way to represent what action? 1. [X] A method call 1. [ ] Instantiation of an object 1. [ ] Storing a value in a variable 1. [ ] Clearing unused memory # Interface An **interface** for a class, such as an API described in that class's documentation, is essentially a list of what? 1. [X] Public methods 1. [ ] Private methods 1. [ ] Public attributes 1. [ ] Private attributes # OOP Interface In object-oriented programming, an **interface** is a special type of class that performs what function? 1. [X] Defines the methods required in subclasses of the interface 1. [ ] Combines two classes into a single object 1. [ ] Converts private attributes to public accessor methods 1. [ ] Protects data in a superclass # Interface Association When a class implements an interface, we would describe that as what type of association in UML? 1. [X] Weak is-a 1. [ ] Strong is-a 1. [ ] Weak has-a 1. [ ] Strong has-a # Multiple Inheritance True or false: in most object-oriented programming languages, a class may implement, or inherit from, multiple interfaces? 1. [X] True 1. [ ] False # Shared Types True or false: in object-oriented programming, two objects created from classes that implement the same interface can be treated as having the same type? 1. [X] True 1. [ ] False # Inheritance In object-oriented programming, **inheritance** is best described by what statement? 1. [X] Driving part of a class definition from an existing class 1. [ ] Storing a value in multiple variables 1. [ ] Creating an interface for each method 1. [ ] Separating state and behavior in a class # Interface Association When a class inherits from another class, we would describe that as what type of association in UML? 1. [ ] Weak is-a 1. [X] Strong is-a 1. [ ] Weak has-a 1. [ ] Strong has-a # Protected In object-oriented programming, a **protected** attribute is best described by what statement? 1. [X] Only accessible to the declaring class and derived classes 1. [ ] Read-only outside the declaring class 1. [ ] Not shown in UML diagrams 1. [ ] Cannot be inherited by derived classes # Abstract In object-oriented programming, an **abstract class** is best described by which statement? 1. [X] A class that exists only to be derived from, not instantiated 1. [ ] A class containing only attributes, but no methods 1. [ ] A class containing only methods, but no attributes 1. [ ] A class that does not implement any interfaces # Casting **Casting** in object-oriented programming is best described by which statement? 1. [X] Transforming a value from one data type to another 1. [ ] Storing an element in a list of similar elements 1. [ ] Expanding a variable's value into an attribute 1. [ ] Inheriting a single method from an interface # Duck Typing In Python, the term **duck typing** is used to describe what aspect of the language? 1. [X] Python allows developers to treat objects as any compatible type without casting 1. [ ] Python does not know what type is stored in a variable at any given time 1. [ ] Python only allows single inheritance 1. [ ] Python classes must include an explicit "duck type" for inheritance purposes # Checking Types True or false: both Java and Python include a special method for determining if a particular object is compatible with a given type? 1. [X] True 1. [ ] False # Message Dispatching In object-oriented programming, **message dispatching** is best described by what statement? 1. [X] How a language decides which implementation of an inherited method to invoke at runtime 1. [ ] How a derived class updates an attribute in the base class 1. [ ] How to determine the type of an object after instantiation 1. [ ] How a base class can update attributes in all derived classes # Method Overriding Which of the following is an example of **method overriding** in object-oriented programming? 1. [X] A method in a derived class that replaces a method of the same name in the base class 1. [ ] Two methods in the same class with the same name that accept different parameters 1. [ ] Replacing a static method with a non-static method of the same name 1. [ ] Converting a method that doesn't return a value into a method that does return a value # Method Overloading Which of the following is an example of **method overloading** in object-oriented programming? 1. [ ] A method in a derived class that replaces a method of the same name in the base class 1. [X] Two methods in the same class with the same name that accept different parameters 1. [ ] Replacing a static method with a non-static method of the same name 1. [ ] Converting a method that doesn't return a value into a method that does return a value