What is the main disadvantage of the Bubble Sort algorithm in terms of performance?
- It has a time complexity of O(n^2) in the worst case, making it inefficient for large datasets.
- It is not a stable sorting algorithm, leading to unpredictable results when sorting objects with equal keys.
- It is not an in-place sorting algorithm, which means it requires additional memory for sorting.
- It requires additional memory space to perform sorting, increasing its space complexity.
The main disadvantage of Bubble Sort is its worst-case time complexity of O(n^2), which makes it inefficient for sorting large datasets. It is a comparison-based sorting algorithm, and its performance degrades significantly as the dataset size increases. Its stability and in-place sorting characteristics are not the primary factors affecting its performance.
In which scenario would you choose an abstract class over an interface?
- When you want to achieve complete abstraction and hide the implementation details of a class.
- When you want to define constants and static methods that are common to a group of related classes.
- When you want to ensure multiple inheritance of behavior without worrying about method implementation conflicts.
- When you want to provide a common base class with some shared functionality and allow derived classes to implement additional methods.
You would choose an abstract class over an interface when you want to provide a common base class with some shared functionality and allow derived classes to implement additional methods. Abstract classes can have both abstract and concrete methods, making them suitable for situations where you need to provide a common structure along with partial implementation.
Which method is typically overridden to handle an event in JavaFX?
- handle()
- handleEvent()
- init()
- start()
In JavaFX, to handle an event, you typically override the handle() method. This method is part of the EventHandler interface, and you provide your custom event-handling logic within it. The other options, such as start(), are methods used for different purposes in JavaFX applications.
To check whether the socket is bound, the ________ method can be used.
- boundStatus()
- checkBound()
- isBound()
- verifySocketBound()
In Java, you can use the isBound() method to check whether a socket is bound or not. This method returns true if the socket is bound, otherwise false.
The “effectively final” concept in the context of Lambda expressions refers to ________.
- Variables that are static
- Variables that are unused
- Variables that don't change
- Variables with final keyword
In the context of Lambda expressions, "effectively final" refers to variables that are not supposed to change after they are initially assigned a value. Lambda expressions can capture and use local variables from their surrounding scope, but these variables must be effectively final, meaning they are not modified after being captured by the lambda. This is to ensure the consistency of captured variables in the lambda's behavior.
What will be the output of the following code snippet: System.out.println(10 + 20 + "Hello" + 30 + 40);?
- 100200Hello3040
- 1020Hello3040
- 5070Hello
- Hello10203040
In Java, when you use the + operator with both numbers and strings, it performs left-to-right addition. So, the numbers are added first, and then the result is concatenated with the strings. The correct output is "1020Hello3040."
What is the role of the JavaFX Application Thread?
- To execute long-running tasks without affecting the application's responsiveness.
- To handle background tasks and data processing in a JavaFX application.
- To manage the user interface (UI) and handle user input events.
- To synchronize communication between the server and the client.
The JavaFX Application Thread, also known as the JavaFX UI thread, is responsible for managing the user interface (UI) and handling user input events in a JavaFX application. It ensures that UI updates and event handling are done in a thread-safe manner, preventing UI freezes and glitches. This thread is crucial for providing a responsive and smooth user experience in JavaFX applications.
The ________ method is used to move the thread into the Ready/Runnable state.
- join()
- sleep()
- start()
- wait()
The "start()" method is used to move a thread into the Ready/Runnable state in Java. When a thread is started using "start()", it becomes eligible for execution, and the JVM schedules it for execution at the appropriate time.
How can you access variables in the surrounding scope from a lambda expression?
- They are automatically accessible within the lambda.
- You can access them using the super keyword.
- You cannot access them.
- You need to pass them as parameters to the lambda expression.
To access variables from the surrounding scope within a lambda expression, you typically need to pass them as parameters to the lambda expression. This is known as "capturing" variables. Lambda expressions in Java can access effectively final local variables and instance variables. Attempting to access non-final variables can result in compilation errors.
Imagine you are developing a gaming application where the player's state needs to be saved and restored effectively. How would you manage the serialization of objects in a way that the player's progress, including scores and levels, is efficiently stored and retrieved?
- Serialize the entire game state, including scores and levels, into a single object for easy storage and retrieval.
- Implement a custom serialization process that selectively serializes only the necessary player progress data, reducing storage and transmission overhead.
- Use a database management system to store and retrieve player progress data, eliminating the need for custom serialization.
- Compress the serialized data before storage and transmission to reduce the data size and optimize efficiency.
In a gaming application, efficient serialization of player progress is essential. Option 2 is the correct choice because it allows for selective serialization, reducing overhead by serializing only the necessary data. Option 1 may result in unnecessary data serialization. Option 3 is a valid approach but involves a different technology (DBMS). Option 4 focuses on data size optimization but doesn't address the serialization process itself.
When using PrintWriter, the method ________ can be used to flush the stream and check its error state.
- checkError()
- close()
- flush()
- write()
In PrintWriter, the method checkError() can be used to flush the stream and check its error state. This method is handy when you want to make sure that all data is written and no errors occurred.
The ________ method of HttpURLConnection class is used to make the connection to the remote object referred by the URL.
- connect()
- createConnection()
- makeConnection()
- openConnection()
To make a connection to the remote object referred to by a URL using HttpURLConnection, you use the openConnection() method. This method initializes and opens a connection to the specified URL. The other options are not standard methods for this purpose.