Initialization of only few values of c# array?

Question

I am trying to write a program in which, I want to initialize 4 starting values of an array, while the other 16 will be entered manually from the console.

For this I have written the following code:

int[] intArray = new int[20] { 20, 22, 23, 0 }; 

But I am getting the following exception: "An array initializer of '20' is expected"

I know that it can be done by this syntax :

int[] intArray = new int[20];
intArray[0] = 20;
intArray[1] = 22;
intArray[2] = 23;
intArray[3] = 0;

I would like to know if this can be achieved in one line.

Answer 1

If you're going to be needing this frequently, you could create your own extension method to populate the values in an existing array:

int[] intArray = new int[20].Populate(20, 22, 23, 0); 

Sample implementation:

public static class ListExtensions
{
    public static TList Populate<TList, TElement>(this TList list, params TElement[] values)
        where TList : IList<TElement>
    {
        // TODO: argument validation

        for (int i = 0; i < values.Length; i++)
            list[i] = values[i];

        return list;
    }
}