Editing Comparison of C Sharp and Java (section)

=== Task-based parallelism for C# ===
With .NET Framework 4.0, a new task-based programming model was introduced to replace the existing event-based asynchronous model. The API is based around the {{mono|Task}} and {{code|Task<T>}} classes. Tasks can be composed and chained.

By convention, every method that returns a {{mono|Task}} should have its name postfixed with ''Async''.

<syntaxhighlight lang="csharp">
public static class SomeAsyncCode
{
    public static Task<XDocument> GetContentAsync()
    {
        HttpClient httpClient = new HttpClient();
        return httpClient.GetStringAsync("www.contoso.com").ContinueWith((task) => {
            string responseBodyAsText = task.Result;
            return XDocument.Parse(responseBodyAsText);
        });
    }
}

var t = SomeAsyncCode.GetContentAsync().ContinueWith((task) => {
    var xmlDocument = task.Result;
});

t.Start();

</syntaxhighlight>

In C# 5 a set of language and compiler extensions was introduced to make it easier to work with the task model. These language extensions included the notion of {{mono|async}} methods and the {{mono|await}} statement that make the program flow appear synchronous.

<syntaxhighlight lang="csharp">
public static class SomeAsyncCode
{
    public static async Task<XDocument> GetContentAsync()
    {
        HttpClient httpClient = new HttpClient();
        string responseBodyAsText = await httpClient.GetStringAsync("www.contoso.com");
        return XDocument.Parse(responseBodyAsText);
    }
}

var xmlDocument = await SomeAsyncCode.GetContentAsync();

// The Task will be started on call with await.

</syntaxhighlight>

From this [[syntactic sugar]] the C# compiler generates a state-machine that handles the necessary continuations without developers having to think about it.