Questions and Answers
Interfaces in Java can only contain method declarations, not method implementations.
True
Delegation in object-oriented programming refers to a class inheriting the characteristics of another class.
False
Run-time polymorphism allows methods to be determined at compile time.
False
Encapsulation restricts direct access to some of an object's components in order to protect the integrity of the object.
Signup and view all the answers
Inclusion polymorphism allows a variable to reference objects of different classes within the same class hierarchy.
Signup and view all the answers
Each class in Java is allowed to implement multiple interfaces.
Signup and view all the answers
Parameters for method definitions can only be of primitive data types in Java.
Signup and view all the answers
Polymorphism enables the same method to perform different tasks based on the object that invokes it.
Signup and view all the answers
In Java, an interface cannot contain any methods with implementations.
Signup and view all the answers
Delegation is considered more appropriate than inheritance in many scenarios.
Signup and view all the answers
Overloading methods requires that the methods differ in their return type.
Signup and view all the answers
Encapsulation is the concept of restricting access to certain details of an object.
Signup and view all the answers
In polymorphism, a method can be executed in different ways depending on the object type it is called on.
Signup and view all the answers
Inheritance allows one class to inherit attributes and methods from multiple classes.
Signup and view all the answers
Parametric polymorphism refers to the use of generics in Java.
Signup and view all the answers
A class can have multiple constructors with the same name as long as they have different return types.
Signup and view all the answers
Java VM errors and hardware problems are typically exceptions that are caught and handled.
Signup and view all the answers
RuntimeExceptions in Java typically indicate programming errors, commonly known as bugs.
Signup and view all the answers
The 'finally' block in Java is executed only if an exception occurs during the execution of the try block.
Signup and view all the answers
It is mandatory for every try block in Java to have at least one catch or finally block.
Signup and view all the answers
Checked exceptions in Java are exceptions that can be anticipated and must be declared in the method signature.
Signup and view all the answers
In Java, the catch blocks can handle only one type of exception each.
Signup and view all the answers
Delegation in Java refers to an object handling requests by passing them to a helper object.
Signup and view all the answers
Polymorphism in Java allows methods to perform different functions depending on the object calling them.
Signup and view all the answers
Study Notes
Exception Handling
-
Try-with-resources statement: Automatically closes resources implementing
java.io.AutoCloseableafter execution. -
Error Types:
- Errors (e.g.,
InternalError,OutOfMemoryError) related to JVM or hardware, typically not caught or thrown. - Runtime Exceptions (e.g.,
ArrayIndexOutOfBoundsException), indicate programming bugs that may lead to application failures. - Exceptions (checked exceptions), expected issues that need handling (e.g.,
IOException).
- Errors (e.g.,
-
Exception Handling Structure:
- try block: Contains code where exceptions may occur.
- catch block: Handles specific exceptions with associated code to resolve issues.
- finally block: Executes code irrespective of exceptions, cleanup operations often placed here.
Object-Oriented Concepts in Java
-
Key Concepts:
- Object: An instance of a class.
- Encapsulation: Restricting access to certain components, enhancing security.
- Class: Blueprint for creating objects.
- Interface: Defines a contract that implementing classes must adhere to.
- Inheritance: Mechanism where one class inherits properties from another.
- Delegation: Assigning responsibility for an operation to another object.
- Polymorphism: Ability to present the same interface for different underlying forms.
Polymorphism
- Inclusion Polymorphism: A single variable can refer to objects of different classes within the same hierarchy or that implement the same interface.
- Operation Polymorphism: Method overloading with the same name but different parameter lists; cannot differ by return type alone.
- Parametric Polymorphism: Use of generics to define classes and methods with type parameters to increase code reusability and flexibility.
Delegation
- Delegation Concept: A class can delegate operations to another class, often favouring delegation over inheritance for cleaner designs.
- Event-Driven Models: Often leverage delegation for event handling within applications, enhancing modularity.
Exception Throwing
- Exceptions are thrown within methods. These can be caught and handled using the previously mentioned
try-catch-finallystructure. Eachtryblock must include at least onecatchorfinallyblock unless used in atry-with-resources.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz focuses on Object-Oriented Programming concepts in Java, specifically on the try-with-resources statement and implementations of the AutoCloseable interface. Test your understanding of key OO principles including encapsulation, inheritance, and more. Perfect for students preparing for the 2024 curriculum.
