C# — Async

Basic async

public static async Task Main()
{
    string result = await FetchDataAsync();
    Console.WriteLine(result);
}

public static async Task<string> FetchDataAsync()
{
    await Task.Delay(1000);
    return "Data loaded";
}

Multiple tasks

public static async Task Main()
{
    var task1 = FetchAsync("url1");
    var task2 = FetchAsync("url2");

    await Task.WhenAll(task1, task2);

    Console.WriteLine(task1.Result);
    Console.WriteLine(task2.Result);
}

Exception handling

try
{
    var result = await RiskyOperationAsync();
}
catch (HttpRequestException ex)
{
    Console.WriteLine($"HTTP error: {ex.Message}");
}

Mini Practice

Write C# code that:

1. Creates an async method
2. Runs multiple tasks concurrently
3. Handles exceptions in async code
4. Uses Task.WhenAll

Up Next

In the next lesson, you'll learn about Events — event-driven programming.