Return value of async method in C# asynchronous programming: Task or void?

When programming asynchronously using C#, the async method can return Task or void. This choice is crucial because it determines the behavior of the method and how it interacts with the calling code.

When will return Task

Usually, when you want to expose the progress or result of an asynchronous operation to the caller, you should return Task. This allows the caller to wait for the task and continue execution after it is completed. Returning Task can also use exception handling and asynchronous modes, such as async-foreach, where the progress of multiple tasks can be monitored.

When will return void

The only suitable case for returning void from the async method is when you explicitly need the return type, such as in an event handler or UI callback. In these cases, the caller should not be able to wait for the method, and the async and await keywords are not required. avoid top level

method Methods marked

have special semantics and should be used with caution. They represent top-level asynchronous operations and have different exception handling rules than methods that return tasks. Exceptions in the top level void method are treated as unhandled exceptions and can lead to unexpected behavior. For example, consider the following code:

public static async void AsyncMethod2(int num)
{
    await Task.Factory.StartNew(() => Thread.Sleep(num));
}

is unnecessary and may be problematic because:

Exceptions in the
1. method will not be handled and may cause the application to behave abnormally.
It is best to use the

method and the await keyword to ensure correct exception handling and maintain the ability to track and manage asynchronous operations.