C# Async & Await

Asynchronous programming with Task.

❮ Previous Next ❯

Asynchronous code keeps apps responsive while waiting for slow work (network, files, databases).

Mark a method async and return Task or Task<T>.
await waits for a task without blocking the thread.
Task.WhenAll() runs several tasks in parallel and waits for all.

Key Takeaways: C# Async & Await

Mastering C# Async & Await helps you write clean and reliable C# code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.

C# Async & Await Code Example

static async Task<string> DownloadAsync(string name, int ms)
{
    await Task.Delay(ms);   // simulate network work
    return $"{name} downloaded";
}

var watch = System.Diagnostics.Stopwatch.StartNew();
var results = await Task.WhenAll(
    DownloadAsync("report.pdf", 1000),
    DownloadAsync("photo.jpg", 800),
    DownloadAsync("data.csv", 600));

foreach (var r in results) Console.WriteLine(r);
Console.WriteLine($"Total ~{watch.ElapsedMilliseconds / 100 * 100} ms (in parallel)");

Output

report.pdf downloaded
photo.jpg downloaded
data.csv downloaded
Total ~1000 ms (in parallel)

Run this example on your own computer. The "Get Started" lesson shows how to set it up.

C# Async & Await Practice Exercises

Check what you learned in “C# Async & Await”.

/ 2 solved

Fill in the blank

Mark the method as asynchronous.

static  Task<string> DownloadAsync() { }

✓ Correct! Not quite. Try again.

Multiple choice

Which method runs several tasks and waits for all of them?

Task.WhenAll() Task.Wait() Task.Run() Task.Join()

✓ Correct! Not quite. Try again.

to save your exercise progress.

Finished this lesson?

Mark it complete to track your progress.

Stuck on something?

Ask the community in the CodesInTech forum.

Need a developer?

Learning on your own is great — and when you need professional help, our team builds custom software, websites and mobile apps for clients worldwide.

Explore Our Services

C# Async & Await

💡 Key Takeaways: C# Async & Await

C# Async & Await Code Example

C# Async & Await Practice Exercises

Key Takeaways: C# Async & Await