Podcast
Questions and Answers
Which of the following most likely indicates that you have chosen a good name for your class? (Select all that apply)
Which of the following most likely indicates that you have chosen a good name for your class? (Select all that apply)
Which of the following questions should you ask yourself in order to determine if you have named your class properly?
Which of the following questions should you ask yourself in order to determine if you have named your class properly?
Which of the following would be an appropriate name for a game-related class?
Which of the following would be an appropriate name for a game-related class?
Which of the following would be an appropriate name for a class used in an inventory application?
Which of the following would be an appropriate name for a class used in an inventory application?
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You are designing an application to support an automobile rental agency. Which of the following probably should NOT be represented as an object?
You are designing an application to support an automobile rental agency. Which of the following probably should NOT be represented as an object?
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You are designing an application to support a veterinary clinic. Which of the following probably should NOT be represented as an object?
You are designing an application to support a veterinary clinic. Which of the following probably should NOT be represented as an object?
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Classes often correspond to ____ in a requirements description.
Classes often correspond to ____ in a requirements description.
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A/an ____ represents a set of objects with the same behavior.
A/an ____ represents a set of objects with the same behavior.
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After you have identified a set of classes needed for a program, you should now ____.
After you have identified a set of classes needed for a program, you should now ____.
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A CRC card describes ____.
A CRC card describes ____.
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When using the CRC method, other classes that are needed to fulfill the responsibilities of a given class are called its ____.
When using the CRC method, other classes that are needed to fulfill the responsibilities of a given class are called its ____.
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When using the CRC method, if you determine that a class cannot carry out a particular task by itself and needs the help of another class to complete the task, you should ____.
When using the CRC method, if you determine that a class cannot carry out a particular task by itself and needs the help of another class to complete the task, you should ____.
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Which of the following is the most important consideration when designing a class?
Which of the following is the most important consideration when designing a class?
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Under which of the following conditions would the public interface of a class be considered cohesive?
Under which of the following conditions would the public interface of a class be considered cohesive?
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A class (ClassOne) is considered to have a dependency on another class (ClassTwo) under which of the following conditions?
A class (ClassOne) is considered to have a dependency on another class (ClassTwo) under which of the following conditions?
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A UML class diagram would be most useful in visually illustrating which of the following?
A UML class diagram would be most useful in visually illustrating which of the following?
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Why is it generally considered good practice to minimize coupling between classes?
Why is it generally considered good practice to minimize coupling between classes?
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Dependency between classes denotes that ____.
Dependency between classes denotes that ____.
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In a UML diagram, dependency is denoted by ____.
In a UML diagram, dependency is denoted by ____.
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If many classes of a program depend on each other, we say that ____.
If many classes of a program depend on each other, we say that ____.
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UML means ____.
UML means ____.
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The dependency relationship is sometimes referred to as the ____ relationship.
The dependency relationship is sometimes referred to as the ____ relationship.
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Which statement correctly describes the class relationship shown in this diagram? CASHREGISTER - - - - - - > COIN
Which statement correctly describes the class relationship shown in this diagram? CASHREGISTER - - - - - - > COIN
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Which of the following code snippets denotes that the Purse class depends on the Wallet class?
Which of the following code snippets denotes that the Purse class depends on the Wallet class?
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Which of the following code snippets denotes that the Pen class depends on the Ink class?
Which of the following code snippets denotes that the Pen class depends on the Ink class?
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Which of the following code snippets denotes that the Kitchen class depends on the Stove class?
Which of the following code snippets denotes that the Kitchen class depends on the Stove class?
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____ is often described as the has-a relationship.
____ is often described as the has-a relationship.
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Which of the following statements is correct?
Which of the following statements is correct?
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Consider the following code snippet: public class Motorcycle { private Tire[] tires; ...} This code is best described as an example of ____.
Consider the following code snippet: public class Motorcycle { private Tire[] tires; ...} This code is best described as an example of ____.
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Consider the following code snippet: public class Motorcycle { private Tire[] tires; ...} Which of the following statements correctly describes the relationship between the Motorcycle and Tire classes?
Consider the following code snippet: public class Motorcycle { private Tire[] tires; ...} Which of the following statements correctly describes the relationship between the Motorcycle and Tire classes?
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Consider the following code snippet: public class Purse { private Coin[] coins; ...} This code is best described as an example of ____.
Consider the following code snippet: public class Purse { private Coin[] coins; ...} This code is best described as an example of ____.
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Consider the following code snippet: public class Purse { private Coin[] coins; ...} Which of the following statements is correct?
Consider the following code snippet: public class Purse { private Coin[] coins; ...} Which of the following statements is correct?
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Aggregation denotes that ____.
Aggregation denotes that ____.
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A CashRegister class contains an array list of Coin objects. This is best described as an example of ____.
A CashRegister class contains an array list of Coin objects. This is best described as an example of ____.
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A Quiz class contains an array of Question objects. This is best described as an example of ____.
A Quiz class contains an array of Question objects. This is best described as an example of ____.
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In a UML diagram, aggregation is denoted by ____.
In a UML diagram, aggregation is denoted by ____.
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In general, you need ____ when an object needs to remember another object between method calls.
In general, you need ____ when an object needs to remember another object between method calls.
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Which statement correctly describes the class relationship shown in this diagram? QUIZ -------- QUESTION
Which statement correctly describes the class relationship shown in this diagram? QUIZ -------- QUESTION
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Which of the following code snippets denotes that the Fleet class aggregates the Taxi class?
Which of the following code snippets denotes that the Fleet class aggregates the Taxi class?
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Which of the following code snippets denotes that the Kitchen class aggregates the Dish class?
Which of the following code snippets denotes that the Kitchen class aggregates the Dish class?
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____ is often described as the is-a relationship.
____ is often described as the is-a relationship.
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Consider the following code snippet: public class Motorcycle extends Vehicle { private Tire[] tires; ...} This code is best described as an example of ____.
Consider the following code snippet: public class Motorcycle extends Vehicle { private Tire[] tires; ...} This code is best described as an example of ____.
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Consider the following code snippet: public class Motorcycle extends Vehicle { ...} Which of the following statements correctly describes the relationship between the Motorcycle and Vehicle classes?
Consider the following code snippet: public class Motorcycle extends Vehicle { ...} Which of the following statements correctly describes the relationship between the Motorcycle and Vehicle classes?
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Consider the following code snippet: public class Motorcycle extends Vehicle { private Tire[] tires; private Engine anEngine; ...} Which of the following statements describing relationships between the Motorcycle, Tire, Engine and Vehicle classes is NOT correct?
Consider the following code snippet: public class Motorcycle extends Vehicle { private Tire[] tires; private Engine anEngine; ...} Which of the following statements describing relationships between the Motorcycle, Tire, Engine and Vehicle classes is NOT correct?
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Consider the following code snippet: public class PowerBoat extends Vessel { private Engine[] engines; ...} This code is best described as an example of ____.
Consider the following code snippet: public class PowerBoat extends Vessel { private Engine[] engines; ...} This code is best described as an example of ____.
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Consider the following code snippet: public class SailBoat extends Vessel { private Engine[] engines; private Sail mainsail; ...} Which of the following statements is NOT correct?
Consider the following code snippet: public class SailBoat extends Vessel { private Engine[] engines; private Sail mainsail; ...} Which of the following statements is NOT correct?
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Consider the following code snippet: public class SailBoat extends Vessel { ...} public class Catamaran extends SailBoat { ...} Which of the following statements is NOT correct?
Consider the following code snippet: public class SailBoat extends Vessel { ...} public class Catamaran extends SailBoat { ...} Which of the following statements is NOT correct?
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Consider the following code snippet: public class Manager extends Employee {private Project[] projects; private Address address; ...} Which of the following statements is NOT correct?
Consider the following code snippet: public class Manager extends Employee {private Project[] projects; private Address address; ...} Which of the following statements is NOT correct?
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In a UML diagram, inheritance is denoted by ____.
In a UML diagram, inheritance is denoted by ____.
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Which of the following statements about class relationships is correct?
Which of the following statements about class relationships is correct?
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Which of the following code snippets denotes that the Lime class inherits from the Citrus class?
Which of the following code snippets denotes that the Lime class inherits from the Citrus class?
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Which of the following code snippets denotes that the Rose class inherits from the Flower class?
Which of the following code snippets denotes that the Rose class inherits from the Flower class?
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When designing classes, if you find classes with common behavior you should ____.
When designing classes, if you find classes with common behavior you should ____.
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In a UML diagram, an interface implementation is denoted by ____.
In a UML diagram, an interface implementation is denoted by ____.
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In a UML diagram, the relationship symbol shown below denotes ____.
In a UML diagram, the relationship symbol shown below denotes ____.
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In a UML diagram, the relationship symbol shown below denotes ____.
In a UML diagram, the relationship symbol shown below denotes ____.
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In a UML diagram, the relationship symbol shown below denotes ____.
In a UML diagram, the relationship symbol shown below denotes ____.
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Study Notes
Class Naming and Responsibilities
- A good class name clearly indicates what an object represents, enhancing readability and maintainability.
- Class names should visualize an object; they should not be mere verbs but should clarify the purpose or role of the class.
Selecting Class Names
- Appropriate class names for games should be simple and intuitive, such as
InitialLevel
, which indicates clear functionality. - For an inventory application, a name like
Product
reflects core class responsibilities and is suitable.
Object Representation
- In applications like automobile rentals or veterinary clinics, certain concepts, like payment amounts or drug dosages, may not require object representation as standalone entities.
Class Characteristics
- Classes typically correspond to nouns in requirement descriptions, signifying the objects or concepts being modeled.
- A class encapsulates a set of objects with shared behavior, referred to as a "class."
Behaviors and Relationships
- Identify necessary behaviors for each class before code writing to ensure an organized method of development.
- CRC (Class-Responsibility-Collaborator) cards detail a class, its responsibilities, and its collaborating classes.
Cohesion and Dependencies
- A cohesive public interface means all features relate to the concept the class represents, enhancing clarity and usability.
- Dependency between classes happens when one class requires another’s objects to fulfill functions. It is visually represented in UML diagrams as a dashed line with an open arrow tip.
Coupling Considerations
- Minimizing coupling between classes is vital as it enhances maintainability and code reuse, reducing complexity.
UML Diagrams
- UML diagrams visually represent class relationships, with dependencies illustrated by dashed lines. Aggregation is depicted with solid lines and diamond symbols next to the aggregating class.
Inheritance and Relationship Types
- Inheritance represents an is-a relationship, while aggregation represents a has-a relationship, each serving different design needs.
- Aggregation indicates one class contains references to another class, exemplified by a class containing an array or collection of objects from another class.
Code Snippets and Class Relationships
- Code snippets illustrate various relationships. For example, when a class contains a collection of another class's objects, it's aggregation.
- Inheritance is denoted by extending a class, indicating the child class derives from the parent class, which supports shared behavior and properties.
Best Practices in Class Design
- When faced with common behaviors across classes, encapsulate shared behaviors into a superclass to adhere to DRY (Don't Repeat Yourself) principles.
- Interfaces in UML diagrams signify relationships and are represented with distinct notation (dashed lines with closed arrow tips) to demonstrate functionality.
Key Concepts
- Dependency denotes a use relationship among classes, critical in structuring complex programs.
- Understanding different types of relationships (aggregation, inheritance, dependency) enhances object-oriented design skills and code organization.
Studying That Suits You
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Description
Test your knowledge with these flashcards for Chapter 12 of AP Computer Science. This quiz focuses on key concepts like class naming and object representation in programming. Perfect for exam revision and self-assessment.