Visual Programming MCQs with Answers
Practice important Visual Programming MCQs with answers and explanations.
Chapter: 35
Q641:
What is the primary purpose of using async and await in C#?
A. To simplify asynchronous programming and make the code easier to read and maintain
B. To ensure that methods execute synchronously and block the main thread
C. To eliminate the need for threads and concurrency in code
D. To manage parallel execution of tasks without using the Task class
Correct Answer:
A
Chapter: 35
Q642:
How does the async keyword affect a method's return type?
A. It allows the method to return a Task or Task<T>, enabling asynchronous operations
B. It automatically changes the method to return void for event handlers
C. It ensures that the method's return type is always void regardless of its content
D. It converts the method into a synchronous method that blocks until completion
Correct Answer:
A
Chapter: 35
Q643:
What does the await keyword do when used in an async method?
A. It pauses the execution of the method until the awaited task completes
B. It immediately executes the awaited task in a new thread
C. It converts the method into a synchronous operation that blocks until the awaited task finishes
D. It ensures the method runs in parallel with other tasks
Correct Answer:
A
Chapter: 35
Q644:
How does the Task.Run method handle asynchronous operations compared to a direct method call?
A. It schedules the method to run asynchronously on a thread pool thread
B. It executes the method synchronously in the calling thread
C. It creates a new thread for each operation, which is inefficient
D. It blocks the calling thread until the operation completes
Correct Answer:
A
Chapter: 35
Q645:
What is the difference between async Task and async Task<T> methods?
A. async Task methods do not return a result, while async Task<T> methods return a result of type T
B. async Task<T> methods are synchronous, while async Task methods are asynchronous
C. async Task methods can only be used with void, while async Task<T> methods can use any return type
D. There is no difference; both return the same type of Task
Correct Answer:
A
Chapter: 35
Q646:
In the code provided, what is the purpose of the TaskCompletionSource<T> class?
A. It allows manual control over task completion, including setting results and handling exceptions
B. It automatically manages the lifecycle of tasks without requiring manual intervention
C. It simplifies the creation of tasks by automatically providing results and handling errors
D. It ensures that tasks are always executed in parallel without exceptions
Correct Answer:
A
Chapter: 35
Q647:
How does await Task.Delay(5000) behave in an asynchronous method?
A. It pauses the method's execution for 5 seconds without blocking the main thread
B. It blocks the entire application for 5 seconds
C. It executes the delay synchronously, blocking the calling thread
D. It creates a new thread that waits for 5 seconds before continuing execution
Correct Answer:
A
Chapter: 35
Q648:
What is the advantage of using CancellationToken in asynchronous methods?
A. It allows methods to be cancelled mid-execution and supports cooperative cancellation
B. It automatically cancels tasks after a specified time without needing additional code
C. It ensures that tasks are executed sequentially without any interruptions
D. It manages thread synchronization and avoids race conditions
Correct Answer:
A
Chapter: 35
Q649:
How is progress reporting handled in asynchronous methods according to the content?
A. By using IProgress<T> interface or Progress<T> class to report progress updates in a thread-safe manner
B. By directly updating the UI with progress information on the main thread
C. By using global variables to track progress and update them from different threads
D. By handling progress reporting through synchronous methods only
Correct Answer:
A
Chapter: 35
Q650:
What does Task.WhenAny do in task combinators?
A. It returns the first task that completes among the given tasks
B. It waits for all tasks to complete and returns the results of the fastest one
C. It combines the results of multiple tasks into a single task
D. It cancels all tasks except for the first one that completes
Correct Answer:
A
Chapter: 35
Q651:
How does await affect method execution when used with Task.Run?
A. It ensures the method waits for the completion of the task scheduled by Task.Run
B. It starts the task in a new thread and immediately returns from the method
C. It executes the task synchronously, blocking the main thread until the task finishes
D. It allows the method to continue executing without waiting for the task to complete
Correct Answer:
A
Chapter: 35
Q652:
What is the benefit of using async lambdas compared to traditional lambda expressions?
A. They allow for asynchronous operations inside lambda expressions and simplify async code
B. They automatically handle exceptions and cancellation without additional code
C. They convert all lambda expressions into asynchronous methods
D. They eliminate the need for await when using lambda expressions
Correct Answer:
A
Chapter: 35
Q653:
In the provided code, what does the catch block handle in asynchronous methods?
A. It handles exceptions that occur during the execution of asynchronous operations
B. It ensures that the task completes successfully without any errors
C. It cancels the task if an error occurs during execution
D. It automatically retries the task upon failure
Correct Answer:
A
Chapter: 35
Q654:
What does await Task.Delay(5000, cancellationToken) do with respect to cancellation?
A. It respects the provided cancellationToken and will throw an exception if cancellation is requested
B. It cancels the delay operation immediately and does not wait for the specified time
C. It ignores the cancellationToken and always completes after 5 seconds
D. It ensures the task is completed even if cancellation is requested
Correct Answer:
A
Chapter: 36
Q655:
What is the main difference between Task.WhenAny and Task.WhenAll?
A. Task.WhenAny returns the first completed task, while Task.WhenAll waits for all tasks to complete
B. Task.WhenAll returns the first completed task, while Task.WhenAny waits for all tasks to complete
C. Task.WhenAny and Task.WhenAll perform the same function but with different names
D. Task.WhenAny waits for all tasks to complete, while Task.WhenAll returns the first completed task
Correct Answer:
A
Chapter: 36
Q656:
How does the Task.WhenAny method behave if one of the tasks fails?
A. It immediately returns the failed task's result
B. It throws an exception if any task fails and stops waiting for other tasks
C. It returns the first completed task, regardless of whether it succeeded or failed
D. It cancels all remaining tasks and does not return any results
Correct Answer:
C
Chapter: 36
Q657:
What does the Task.WhenAll method do when used with tasks that throw exceptions?
A. It aggregates all exceptions from the tasks into a single AggregateException and rethrows it
B. It ignores exceptions and returns successfully completed tasks only
C. It terminates execution and returns a partial result if any task fails
D. It handles exceptions individually and returns results of the successful tasks only
Correct Answer:
A
Chapter: 36
Q658:
What is the purpose of the Parallel.For method in the Task Parallel Library?
A. To execute a loop in parallel, dividing the work among multiple threads
B. To execute a loop sequentially without parallelism
C. To create a new thread for each iteration of the loop
D. To synchronize the execution of a loop across different threads
Correct Answer:
A
Chapter: 36
Q659:
What does the Parallel.ForEach method do with a collection of items?
A. It executes a specified action on each item in the collection in parallel
B. It processes each item sequentially in the order they appear in the collection
C. It combines all items into a single result and processes them in parallel
D. It ensures that each item in the collection is processed by a separate thread
Correct Answer:
A
Chapter: 36
Q660:
How can you handle exceptions in parallel tasks using Parallel.For or Parallel.ForEach?
A. By using try-catch blocks inside the loop body to catch and handle exceptions
B. By specifying a custom exception handler for the entire parallel operation
C. By using a global exception handler that catches all exceptions thrown by parallel tasks
D. By allowing exceptions to propagate without handling them
Correct Answer:
A