Passing Arrays Using out (C#)

Like all out parameters, an out parameter of an array type must be assigned before it is used; that is, it must be assigned by the callee. For example:

static void TestMethod1(out int[] arr)
{
    arr = new int[10];   // definite assignment of arr
}
//*****************************

//example:

class TestOut
{
    static void FillArray(out int[] arr)
    {
        // Initialize the array:
        arr = new int[5] { 1, 2, 3, 4, 5 };
    }

    static void Main()
    {
        int[] theArray; // Initialization is not required

        // Pass the array to the callee using out:
        FillArray(out theArray);

        // Display the array elements:
        System.Console.WriteLine("Array elements are:");
        for (int i = 0; i < theArray.Length; i++)
        {
            System.Console.Write(theArray[i] + " ");
        }

        // Keep the console window open in debug mode.
        System.Console.WriteLine("Press any key to exit.");
        System.Console.ReadKey();
    }
}
    /* Output:
        Array elements are:
        1 2 3 4 5        
    */