Generic Classes Implementation Quiz

What is a potential issue with implementing a List MenuList based on type 'Object'?

What does overriding List::add to improve type safety violate?

What feature do generics allow in programming?

In Java, what is the purpose of actual type parameters in generic classes?

What does Java assume upon missing type parameter for generic classes?

Which of the following is not allowed for actual type parameters in Java generic classes?

What does autoboxing / unboxing help to avoid in Java?

What does type erasure in Java ensure without run-time impact?

What is the disadvantage of generic classes in Java?

What does covariance allow in inheritance and generic classes in Java?

What is the design goal of a class API in Java?

What does the 'printAll' method demonstrate in Java?

What additional method for Stack in Java is considered inflexible?

What does the additional method 'pushAll(Iterable src)' aim to achieve in Java?

What is the primary purpose of the 'Stack' class in Java?

What does the 'Iterable' interface allow in Java?

What is the primary concern with implementing a List MenuList based on type 'Object'?

What is the purpose of overriding List::add to improve type safety?

What do generics allow in programming languages?

What is the impact of implementing a List MenuList based on type 'Object'?

In Java, what does type erasure ensure without run-time impact?

What does the 'Iterable' interface allow in Java?

What is the primary purpose of the 'Stack' class in Java?

What additional method for Stack in Java is considered inflexible?

What is a potential issue with implementing a List MenuList based on type 'Object'?

What does the 'printAll' method demonstrate in Java?

What does autoboxing / unboxing help to avoid in Java?

What does the 'pushAll(Iterable src)' method aim to achieve in Java?

What does covariance allow in inheritance and generic classes in Java?

What does Java assume upon missing type parameter for generic classes?

What does the 'Iterable' interface allow in Java?

What is the disadvantage of generic classes in Java?

Java generic classes can be instantiated without actual type parameter. 'Object' is assumed upon missing type parameter.

Java base types (primitives) are allowed for actual type parameters in generic classes.

Java compilers apply type erasure, which ensures type safety without run-time impact.

Autoboxing / unboxing in Java helps to avoid type conversions.

Combining inheritance and generics in Java is desirable due to its flexibility and reliability.

The 'printAll' method in Java demonstrates flexibility and type safety in class API design.

The additional method 'pushAll(Iterable src)' for Stack in Java is considered inflexible.

Type erasure in Java ensures type safety without run-time impact.

The design goal of a class API in Java is flexibility, type safety, readability, and self-documenting API.

Covariance allows List to be a subtype of List in Java.

The 'Iterable' interface in Java allows for flexible and safe additional methods for the 'Stack' class.

The 'pushAll(Iterable src)' method for Stack in Java aims to achieve flexibility and safety.

Generic classes in Java allow to abstract over types.

Implementing a List MenuList based on type 'Object' is considered questionable due to frequent type conversions necessary.

Overriding List::add to improve type safety in Java violates the principle of substitutability.

Covariance allows for assigning a List of a subtype to a List of a supertype in Java.

Java's generic classes feature has been available since Java 5.

The 'pushAll(Iterable src)' method in Java aims to add all elements from the source Iterable to the stack.

Type erasure in Java ensures no run-time impact.

The 'printAll' method demonstrates the use of generics in Java.

Java's 'Iterable' interface allows for iteration over a collection of elements.

Autoboxing / unboxing helps to avoid type safety issues in Java.

The design goal of a class API in Java includes ensuring flexibility and extensibility.

Generics in Java provide a way to specify formal type parameters in classes.

What is the purpose of type erasure in Java generic classes?

What are the advantages of generic classes in Java?

What is a potential disadvantage of generic classes in Java?

What does the 'Stack' class API design aim to achieve in Java?

What is the primary concern with implementing a List MenuList based on type 'Object' in Java?

What does the additional method 'pushAll(Iterable src)' for Stack in Java aim to achieve?

Why is combining inheritance and generics desirable in Java?

What does the 'printAll' method in Java aim to demonstrate in class API design?

What is the primary purpose of the 'Stack' class in Java?

What does covariance allow in inheritance and generic classes in Java?

What does autoboxing / unboxing help to avoid in Java?

What is the role of Java reflection in relation to generic classes?

Explain the potential issue with implementing a List MenuList based on type 'Object' in Java.

What do generics allow in programming languages?

What is the impact of implementing a List MenuList based on type 'Object' in Java?

What does the 'pushAll(Iterable src)' method aim to achieve in Java?

What is the primary purpose of the 'Stack' class in Java?

What does covariance allow in inheritance and generic classes in Java?

What is the purpose of overriding List::add to improve type safety?

What does autoboxing / unboxing help to avoid in Java?

What feature do generics allow in programming?

What additional method for Stack in Java is considered inflexible?

What is the primary concern with implementing a List MenuList based on type 'Object'?

What is the primary purpose of the 'Stack' class in Java?

Generic Classes allow to abstract over ______

Generic classes in Java allow to abstract over ______

The primary concern with implementing a List MenuList based on type 'Object' is the frequent type ______ necessary

What does ______ allow in inheritance and generic classes in Java?

Java's 'Iterable' interface allows for iteration over a ______ of elements

What is the purpose of overriding List::add to improve type ______?

Type erasure in Java ensures ______ safety without run-time impact

What is the impact of implementing a List MenuList based on type 'Object' in Java?

What is the primary purpose of the 'Stack' class in Java?

Why is combining inheritance and generics desirable in Java?

What is a potential issue with implementing a List MenuList based on type 'Object' in Java?

What does the 'pushAll(Iterable src)' method for Stack in Java aim to achieve?

Java base types (primitives) are not ______ for actual type parameters

Java compilers applies type erase

List l = new ______(); //before Java 5 // vs. List l = new ______(); //before Java 7

Public class NumberList { public void add(T ______) {}; public T get(int index) {}; } NumberList numberList = new NumberList(); NumberList stringList = new NumberList(); //compile-time error.

Expressive and self documenting API Client should not care about typing ______

Public class Stack { public Stack(); public void push(E e); public E pop(); public boolean ______(); }

Public void pushAll(Iterable src) { for (E e : src) push(e); } . //Usage Stack numberStack = new Stack(); Iterable ______ =.; numberStack.pushAll(______);

Public void pushAll(Iterable

Public static boolean ______(T[] array, T object) {.}

Public static void printAll(List l) { for (Object o: l) { System.out.println(o); } } hardly usable List ______ = new ArrayList(); printAll(______); //compile-time error.

Public static void printAll(List l) { for (Object o: l) { System.out.println(o); } } ______ List stringList = new ArrayList(); printAll(stringList);

Public static void ______(List l) { for (Object o: l) { System.out.println(o); } } hardly usable List stringList = new ArrayList(); ______(stringList);

Java also provides generic ______ public static boolean contains(T[] array, T object) {.}

Which interface does not specify duplicity, sequence, or contained objects?

Which class provides a view of unmodifiable, synchronized, or subset collections?

Which interface provides the forEach method in Java 8?

Which class allows elements to be accessed through an iterator and supports internal iteration in Java 8?

Which class provides natural order defined by the Comparable interface?

Which class provides an alternative if Comparable does not define the required order?

Which class is responsible for sequential access to its elements in Java 8?

Which class provides a clean separation of concerns with internal iteration in Java 8?

Which method is used to break up implementation into distinct sections with minimal overlap?

Which feature is added in Java 8 to extend the Iterable interface without breaking the API?

What is the primary purpose of class libraries in object-oriented software development?

What challenges do traditional (procedural) libraries face, according to the text?

What does the synthesis of state and behavior in class libraries enable?

What do abstract classes and interfaces enable in class libraries?

What is the purpose of relocating control flow from application into library in class libraries?

What is the role of class hierarchies and object structures in class libraries?

What do object-oriented class libraries aim to achieve through inheritance and dynamic binding?

What is the advantage of using abstract classes in class libraries?

What is the impact of interfaces in class libraries?

What does the structuring of class libraries aim to achieve?

What is the primary purpose of the Open-Closed Principle by B. Meyer?

Why has the Java Class Library evolved with a significant increase in the number of packages and classes over time?

What is the pivotal role of the 'Object' class in the Java class library?

What does the equals contract in Java specify?

What does the recipe for overriding equals in Java involve?

How have collection classes in Java evolved over time?

What has the evolution of collection classes in Java led to?

What is the trend in interfaces for operations on collections/streams in Java?

What is the impact of the evolution of collection classes in Java?

What is the design goal of collection classes in Java?

What is the impact of the equals contract in Java?

Object-oriented class libraries aim to achieve loose coupling through abstractions and information hiding.

The 'Iterable' interface in Java allows for flexible and safe additional methods for the 'Stack' class.

The structuring of class libraries aims to achieve factorization, reusability, and adaptability.

The evolution of collection classes in Java has led to the improvement of flexibility and extensibility.

Combining inheritance and generics is undesirable in Java.

The primary concern with implementing a List MenuList based on type 'Object' in Java is the frequent type casting necessary.

Covariance allows for assigning a List of a subtype to a List of a supertype in Java.

Generic classes in Java allow to abstract over different data types.

The 'printAll' method demonstrates the use of generics in Java.

Java reflection in relation to generic classes ensures run-time type checking.

Abstract classes in Java can have only abstract methods and no concrete methods.

The Collection interface in Java does not have any directly implementing classes or subtypes.

The Comparable interface in Java defines the natural order of elements and is implemented by all base type classes.

In Java, the Iterator interface may optionally add elements to a collection during iteration.

Java 8 added the forEach method to the Iterable interface, allowing for internal iteration.

The AbstractList class in Java is a concrete class and can have multiple implementations per interface.

The separation of concerns in Java 7 (or earlier) collections provides only external iteration, where iteration and operation on elements are intermingled.

The primary role of the AbstractMap class in Java is to provide a sorted set with a defined sort order.

The separation of concerns in Java aims to break up implementation into distinct sections with maximal overlap.

Java compilers do not apply type erasure, which ensures type safety without run-time impact.

True or false: The Open-Closed Principle by B. Meyer states that a class should be closed for extension but open for modification.

True or false: The equals contract in Java specifies that the equals method should be reflexive, symmetric, transitive, consistent, and handle null references.

True or false: The recipe for overriding equals in Java involves only an identity check and comparison of attributes.

True or false: Collection classes in Java have evolved from more flexible and comprehensive designs in Java 1.0 to simple and inflexible designs in Java 1.2.

True or false: The evolution of collection classes in Java has led to more comprehensive functionality, better performance, and a pay-as-you-go approach.

True or false: The Java Class Library has evolved with a significant decrease in the number of packages and classes over time.

True or false: The 'Object' class in Java is not pivotal as it does not provide any important methods for other classes.

True or false: The equals method override in Java cannot result in potential violations of symmetry and transitivity.

True or false: The impact of class libraries on software development includes disadvantages such as more in-house development and narrower test coverage.

True or false: The trend for collection classes in Java is towards larger and more interfaces for operations on collections/streams.

What are some of the challenges faced by traditional (procedural) libraries, according to the text?

What is the primary goal of the structuring of class libraries, as mentioned in the text?

What does the synthesis of state and behavior in class libraries enable?

What is the design goal of collection classes in Java, as per the text?

What are some of the features enabled by inheritance and dynamic binding in class libraries?

What is the trend in interfaces for operations on collections/streams in Java?

What is the impact of the evolution of collection classes in Java, as mentioned in the text?

What is the primary concern with implementing a List MenuList based on type 'Object', according to the text?

What does autoboxing / unboxing help to avoid in Java, as per the text?

What is the primary purpose of the 'Stack' class in Java, according to the text?

Explain the purpose of abstract classes in the context of class libraries in Java.

What is the main reason for the existence of the Collection interface in Java?

Explain the Open-Closed Principle in object-oriented software development according to B. Meyer's definition.

Explain the concept of separation of concerns in the context of class libraries.

What is the significance of the 'Object' class in the Java class library?

What is the difference between external and internal iteration in Java collections?

What are the key requirements specified by the equals contract in Java?

Describe the role of the Comparable and Comparator interfaces in Java collections.

What are the essential steps involved in overriding the equals method in Java?

Explain the impact of implementing a List MenuList based on the type 'Object' in Java.

How have collection classes in Java evolved over time?

What is the aim of using abstract classes and interfaces in the design of class libraries?

What are the advantages of the impact of class libraries on software development?

Explain the concept of separation of concerns in class libraries and how it relates to the design of Java collections.

What is the trend in the design of collection classes in Java?

What is the primary role of the Collection interface in Java?

What does the text specifically focus on in relation to object-oriented software development?

Explain the concept of fail-fast and its relevance in the context of Java collections.

What is the impact of the evolution of collection classes in Java?

How has the Java Class Library evolved over time?

Abstract classes provide a __________ for implementation

Concrete methods may be replaced by more __________ implementations

Interfaces specify types, abstract classes help __________

Internal iteration makes a clean separation of __________

Java 8 adds forEach method as a default implementation in the __________ interface

Creating views on collections allows for e.g. unmodifiable, synchronized, __________ views

Subtyping contract cannot always be __________

Separation of concerns breaks up implementation into distinct sections with minimal __________

The design goal of a class API in Java includes ensuring __________ and extensibility

External iteration makes a clean separation of concerns limited with Java 7 (or __________)

Object-Oriented Software Development – Class Libraries 2 Contents Class libraries Java class library Case study: Java collection classes Structuring of class libraries ff Dr. Bruno Schä er © 2023 Object-Oriented Software Development – Class Libraries

Programming languages provide only limited functionality Additional functionality: libraries rather than language extensions Math functions, input/output, etc. Language and library are tightly coupled From subroutine collections to modules Challenges Abstractions Factorization Reusability and adaptability ff Dr. Bruno Schä er © 2023 Object-Oriented Software Development – Class Libraries

Synthesis of state and behavior Abstractions and information hiding enable loose coupling Inheritance and dynamic binding Adaptation to new requirements Abstract classes ➜ factorization, generalization, and speci cation Interfaces ➜ factorization, type speci cation Relocating control ow from application into library Enables exible design of complex problems Class hierarchies and object structures Modeling of problem domains Object-Oriented Software Development – ______ fi fi fl ff fl Dr.

Traditional (Procedural) Libraries

Modeling of problem domains Object-Oriented Software Development – Class Libraries

Enables exible design of complex problems Class hierarchies and object structures

Case study: Java collection classes Structuring of class libraries ff Dr. Bruno Schä er © 2023 Object-Oriented Software Development – Class Libraries

Structuring of class libraries ff Dr. Bruno Schä er © 2023 Object-Oriented Software Development – Class Libraries

Structuring of class libraries ff Dr. Bruno Schä er © 2023 Object-Oriented Software Development – ______

Class libraries Java class library

Changing requirements should not require code changes, but rather new code should be added in a derived class or a new implementation of an ______

The impact of class libraries on software development includes advantages such as less in-house development, broader test coverage, and frameworks going beyond class ______

The equals contract in Java specifies that the equals method should be reflexive, symmetric, transitive, consistent, and handle ______ references

The recipe for overriding equals in Java involves an identity check, type equality check, comparison of attributes, dealing with null pointers, and overriding ______

Collection classes in Java have evolved from simple and inflexible designs in Java 1.0 to more flexible and comprehensive designs in Java ______

Collection classes include interfaces that define minimal functionality, type hierarchy, and compatibility, and there is a trend towards smaller and more interfaces for operations on ______/streams

The evolution of collection classes in Java has led to more comprehensive functionality, better performance, and a pay-as-you-go approach, demonstrating good object-oriented design for class libraries and ______

The Java Class Library has evolved with a significant increase in the number of packages and classes ______ time

The 'Object' class is pivotal in the Java class library, as all classes are derived from it, and it provides important methods like clone, equals, hashCode, and ______

A comparison of objects example demonstrates how to override the equals method and the potential violations of ______ and transitivity