Creating methods with infinite parameters?

Question

In C# you can do this:

foo = string.Format(\"{0} {1} {2} {3} ...\", \"aa\", \"bb\", \"cc\" ...);

This method Format() accepts in

Answer 1

With the params keyword.

Here is an example:

    public int SumThemAll(params int[] numbers)
    {
        return numbers.Sum();
    }

    public void SumThemAllAndPrintInString(string s, params int[] numbers)
    {
        Console.WriteLine(string.Format(s, SumThemAll(numbers)));
    }

    public void MyFunction()
    {
        int result = SumThemAll(2, 3, 4, 42);
        SumThemAllAndPrintInString("The result is: {0}", 1, 2, 3);
    }

The code shows various things. First of all the argument with the params keyword must always be last (and there can be only one per function). Furthermore, you can call a function that takes a params argument in two ways. The first way is illustrated in the first line of MyFunction where each number is added as a single argument. However, it can also be called with an array as is illustrated in SumThemAllAndPrintInString which calls SumThemAll with the int[] called numbers.

Answer 2

 public string Format(params string[] value)
 {
            // implementation
 }

The params keyword is used