How to use async and await in C#?

The keywords async and await were introduced in C# 5.0. They enable writing asynchronous code in a more readable and maintainable way, using the async/await pattern.

Here is an example of how to use async and await:

public async Task PerformAsyncOperation()
{
    // Prepare data
    string data = await GetDataAsync();

    // Perform an operation on the data
    int result = await PerformOperationAsync(data);

    // Return the result
    return result;
}

In this example, the method PerformAsyncOperation is declared with the async keyword. This indicates that the method contains asynchronous code.

Inside the method, the await keyword is used to wait for an asynchronous operation to complete. In this case, the method GetDataAsync and PerformOperationAsync are both asynchronous operations.

When the await keyword is encountered in the execution of the PerformAsyncOperation method, the method returns an incomplete task to the caller, effectively yielding control back to the caller.

The rest of the method (PerformOperationAsync in this case) continues executing asynchronously, and when the asynchronous operation is complete, the rest of the method is scheduled to run to completion.

In this way, async and await can be used to simplify writing asynchronous code in C#.

Keep in mind that for the await keyword to function properly, the calling method also has to be declared with the async keyword, and should return a Task or Task<T>.

If the method being awaited returns a Task<T>, then the await keyword will return a T to the caller.

The methods being awaited (GetDataAsync and PerformOperationAsync in this case) should also be asynchronous and return a Task or Task<T>.

Here is an example of how these methods could be implemented:

public async Task<string> GetDataAsync()
{
    // Simulate asynchronous data retrieval
    await Task.Delay(1000);

    return "Some data";
}

public async Task<int> Perform