Why might a programmer choose to use package-private (default) access level over private for a method within a class?
- Package-private methods allow access to subclasses, promoting code reusability within the same package.
- Package-private methods are accessible from outside the class, making them more versatile.
- Package-private methods are more restrictive than private methods and provide better encapsulation.
- Private methods cannot be used within a class.
Programmers might choose package-private access level for a method when they want to allow subclasses to access the method for code reuse but restrict access from outside the package. It strikes a balance between encapsulation and reusability, making it a useful choice in certain situations.
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.
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 can you prevent the fall-through behavior in a switch case?
- Fall-through behavior cannot be prevented in a switch case.
- Use the break statement after each case block.
- Use the continue statement after each case block.
- Use the stop statement after each case block.
In Java, you can prevent fall-through behavior in a switch case by using the break statement at the end of each case block. When a break is encountered, the control flow exits the switch statement, preventing the execution of subsequent cases. Without break, fall-through behavior will occur, and all cases after the matched one will be executed.
How do you specify a timeout while trying to connect to a remote socket?
- setConnectionTimeout()
- setSoTimeout()
- setSocketTimeout()
- setTimeout()
To specify a timeout while trying to connect to a remote socket in Java, you can use the setSoTimeout() method on the Socket object. This method sets a maximum time for blocking operations, such as connecting or reading, to complete.
When using a single-thread executor, what happens if a submitted task throws an exception?
- The exception is caught, logged, and the executor continues to execute other tasks.
- The exception is ignored, and the executor continues to execute other tasks.
- The exception is propagated up the call stack to the caller of the submit() method.
- The thread running the task is terminated, and the executor replaces it with a new thread.
In a single-thread executor, when a submitted task throws an exception, it is caught and logged, but the executor continues to execute other tasks. The executor does not terminate due to an exception in a single task; it maintains the single thread for execution.
Which of the following character stream classes should be used to read characters, arrays, and lines efficiently?
- BufferedReader
- CharArrayReader
- FileReader
- InputStreamReader
The BufferedReader class is used to read characters, arrays, and lines efficiently from a character input stream. It provides buffering, which makes reading more efficient. FileReader is used to read characters from files, and InputStreamReader is used for byte-to-character conversion. CharArrayReader is used to read from character arrays.
What will happen if the DriverManager is unable to connect to the database using the provided URL?
- A compilation error will occur
- A runtime exception will be thrown
- An SQLException will be thrown
- It will silently retry to connect in the background
When the DriverManager in JDBC fails to connect to the database using the provided URL, it throws an SQLException. This exception should be handled in your code to gracefully manage the failure and take appropriate actions, such as logging the error or providing a user-friendly message.
The relational operators are often used inside the ______ statement to produce boolean value.
- for
- if
- switch
- while
Relational operators (e.g., <, >, ==) are commonly used inside the "if" statement to create conditions that produce boolean (true/false) values based on comparisons.
The keyword ________ is used to skip the rest of the current loop iteration.
- break
- continue
- exit
- return
In Java, the continue keyword is used to skip the rest of the current loop iteration and move to the next iteration. It is often used in loops like for and while when certain conditions are met, and you want to skip the current iteration and continue with the next one. The other options do not serve this purpose.
In Java, if a class implements an interface and does not provide implementations for all its methods, it must be declared as ________.
- Abstract Class
- Concrete Class
- Final Class
- Static Class
When a class in Java implements an interface but doesn't provide implementations for all the interface methods, it must be declared as an abstract class. This is because an abstract class can have unimplemented methods, while concrete classes need to provide implementations for all interface methods they inherit.
A thread that goes into the ________ state will not be brought back to the running state when its sleep time has elapsed or its operation is complete.
- blocked
- sleeping
- terminated
- waiting
Once a thread enters the "terminated" state, it cannot be brought back to the running state. The thread has completed its execution or has been explicitly terminated and cannot be resumed.