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.
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.
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.
A ______ event is an event that JavaFX propagates up the scene graph from child to parent.
- Bubbling
- Capturing
- Focusing
- Mouse
In JavaFX, a "bubbling" event refers to an event that starts from the source (usually a node) and propagates up the scene graph hierarchy from child to parent nodes. This allows parent nodes to react to events triggered by their children. The other options are not related to event propagation.
How does thread priority impact the order in which threads are executed?
- Thread priority has no impact on the order of thread execution.
- Thread priority is randomly assigned, so there is no fixed order.
- Threads with higher priority are always executed before threads with lower priority.
- Threads with lower priority are always executed before threads with higher priority.
Thread priority in Java can be set using the setPriority() method and can range from 1 to 10, where 1 is the lowest and 10 is the highest priority. Threads with higher priority are given preference, but it's not guaranteed that they will always execute first, as it depends on the thread scheduler and other factors.