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.
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.
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.
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.
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 Java, constructors have the same name as the _______.
- Class
- Method
- Package
- Variable
In Java, constructors have the same name as the class in which they are defined. This naming convention allows you to identify and use the constructor associated with a particular class.
A variable declared as double d = 10.3; occupies ________ bytes of memory.
- 16
- 2
- 4
- 8
In Java, a variable of type "double" occupies 8 bytes of memory. The "double" data type is a 64-bit floating-point type that can hold both integer and fractional values. It requires 8 bytes to store its precision and range, making it suitable for storing large and decimal numbers with high precision.
Envisage a situation where you are developing a high-throughput application where multiple threads are reading and writing to a data structure. Which collection would you select to store data and why?
- ArrayList
- ConcurrentHashMap
- HashSet
- LinkedList
In this scenario, a ConcurrentHashMap is the preferred choice. It's designed for concurrent access by multiple threads, making it suitable for high-throughput applications. Unlike ArrayList, LinkedList, and HashSet, it provides thread-safety without sacrificing performance. It achieves this through a mechanism that allows multiple threads to read concurrently while providing efficient locking for write operations.
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.
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.