Are Parallel.Invoke and Parallel.ForEach essentially the same thing?

Parallel.ForEach goes through the list of elements and can perform some task on the elements of the array.

eg.

Parallel.ForEach(val, (array) => Sum(array));

Parallel.Invoke can invoke many functions in parallel.

eg.

Parallel.Invoke(() => doSum(array),() => doAvg(array),() => doMedian(array));

As from the example above, you can see that they are different in functionality. ForEach iterates through a List of elements and performs one task on each element in parallel, while Invoke can perform many tasks in parallel on a single element.

Parallel.Invoke and Parallel.ForEach (when used to execute Actions) function the same, although yes one specifically wants the collection to be an Array. Consider the following sample:

List<Action> actionsList = new List<Action>            {                () => Console.WriteLine("0"),                () => Console.WriteLine("1"),                () => Console.WriteLine("2"),                () => Console.WriteLine("3"),                () => Console.WriteLine("4"),                () => Console.WriteLine("5"),                () => Console.WriteLine("6"),                () => Console.WriteLine("7"),                () => Console.WriteLine("8"),                () => Console.WriteLine("9"),            };            Parallel.ForEach<Action>(actionsList, ( o => o() ));            Console.WriteLine();            Action[] actionsArray = new Action[]            {                () => Console.WriteLine("0"),                () => Console.WriteLine("1"),                () => Console.WriteLine("2"),                () => Console.WriteLine("3"),                () => Console.WriteLine("4"),                () => Console.WriteLine("5"),                () => Console.WriteLine("6"),                () => Console.WriteLine("7"),                () => Console.WriteLine("8"),                () => Console.WriteLine("9"),            };            Parallel.Invoke(actionsArray);            Console.ReadKey();

This code produces this output on one Run. It's output is generally in a different order every time.

0 5 1 6 2 7 3 8 4 9

0 1 2 4 5 6 7 8 9 3

I'm trying to find a good way of phrasing it; but they are not the same thing.

The reason is, Invoke works on an Array of Action and ForEach works on a List (specifically an IEnumerable) of Action; Lists are significantly different to Arrays in mechanics although they expose the same sort of basic behaviour.

I can't say what the difference actually entails because I don't know, so please don't accept this an an answer (unless you really want too!) but I hope it jogs someones memory as to the mechanisms.

+1 for a good question too.

Edit; It just occurred to me that there is another answer too; Invoke can work on a dynamic list of Actions; but Foreach can work with a Generic IEnumerable of Actions and gives you the ability to use conditional logic, Action by Action; so you could test a condition before saying Action.Invoke() in each Foreach iteration.