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Passing Arrays as Parameters (C# Programming Guide)

Visual Studio 2005

Arrays may be passed to methods as parameters. As arrays are reference types, the method can change the value of the elements.

Passing single-dimensional arrays as parameters

You can pass an initialized single-dimensional array to a method. For example:

PrintArray(theArray);

The method called in the line above could be defined as:

void PrintArray(int[] arr)
{
    // method code
}

You can also initialize and pass a new array in one step. For example:

PrintArray(new int[] { 1, 3, 5, 7, 9 });

Example 1

In the following example, a string array is initialized and passed as a parameter to the PrintArray method, where its elements are displayed:

class ArrayClass
{
    static void PrintArray(string[] arr)
    {
        for (int i = 0; i < arr.Length; i++)
        {
            System.Console.Write(arr[i] + "{0}", i < arr.Length - 1 ? " " : "");
        }
        System.Console.WriteLine();
    }

    static void Main()
    {
        // Declare and initialize an array:
        string[] weekDays = new string[] { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };

        // Pass the array as a parameter:
        PrintArray(weekDays);
    }
}

Output 1

Sun Mon Tue Wed Thu Fri Sat

Passing multidimensional arrays as parameters

You can pass an initialized multidimensional array to a method. For example, if theArray is a two dimensional array:

PrintArray(theArray);

The method called in the line above could be defined as:

void PrintArray(int[,] arr)
{
    // method code
}

You can also initialize and pass a new array in one step. For example:

PrintArray(new int[,] { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 } });

Example 2

In this example, a two-dimensional array is initialized and passed to the PrintArray method, where its elements are displayed.

class ArrayClass2D
{
    static void PrintArray(int[,] arr)
    {
        // Display the array elements:
        for (int i = 0; i < 4; i++)
        {
            for (int j = 0; j < 2; j++)
            {
                System.Console.WriteLine("Element({0},{1})={2}", i, j, arr[i, j]);
            }
        }
    }
    static void Main()
    {
        // Pass the array as a parameter:
        PrintArray(new int[,] { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 } });
    }
}