Class relationships in Java Programming

What is encapsulation in Java?

• Encapsulation in Java is the mechanism of wrapping the data (variables) and code acting on the data (methods) together as a single unit.

• Encapsulation in Java is not related to data hiding

• Encapsulation in Java refers to the process of converting code into bytecode

• Encapsulation in Java involves exposing all class variables as public

Explain the concept of abstraction in Java.

• Abstraction in Java is not relevant to object-oriented programming.

• Abstraction in Java is achieved through concrete classes only.

• Abstraction in Java is achieved through abstract classes and interfaces.

• Abstraction in Java is primarily used for low-level programming tasks.

Define Association in Java programming.

• Association in Java is a way to define classes

• Association in Java is a type of inheritance

• Association in Java programming is a relationship between two classes where one class is aware of the other class.

• Association in Java is a method for declaring methods

Differentiate between Composition and Aggregation in Java.

• Composition in Java is a relationship where the child object can exist independently.

• Composition in Java is a weak relationship where the child object can exist independently.

• Aggregation in Java is a strong relationship where the child object does not exist without the parent object.

• Composition in Java is a strong relationship where the child object does not exist without the parent object.

What are Wrapper classes in Java?

• Wrapper classes are used to wrap objects in Java

• Integer myInt = 5;

• Wrapper classes are used to wrap arrays in Java

• Wrapper classes in Java a class whose object wraps primitive data types.

How is BigInteger class used in Java?

• BigInteger class is used for storing small integers

• BigInteger class can be used when dealing with very large numbers in cryptographic algorithms or mathematical computation

• BigInteger class is used for handling string manipulation in Java

• BigInteger class in Java is used for handling floating-point numbers

Strings in Java are ...

• Strings are not supported in Java, and developers should avoid using them.

• Strings are mutable in Java, making them less reliable for text manipulation.

• Strings are crucial in Java for representing text data, as they are immutable and have various use cases.

• Strings are rarely used in Java and can be replaced by other data types.

Autoboxing: converting primitives into objects

• Integer num = 10;

• char c = ch.charValue();

• int n = num.intValue();

• None is correct

Abstraction is considered a key feature of object-oriented programming because it

• Abstraction complicates design and hinders code reusability.

• Abstraction simplifies design, promotes code reusability, and enhances program structure.

• Abstraction has no impact on program structure.

• Abstraction is only useful in procedural programming.

Give an example of a one-to-many Association in Java.

• Library class with a List attribute representing multiple books associated with the library.

• Car class with a List attribute representing multiple wheels associated with the car.

• Employee class with a List attribute representing multiple departments associated with the employee.

• School class with a List attribute representing multiple students associated with the school.