Passing arrays as arguments in C#

An array is a collection of similar type variables which are referred to by a common name. In C#, arrays are the reference types so it can be passed as arguments to the method. A method can modify the value of the elements of the array. Both single-dimensional and multidimensional arrays can be passed as an argument to the methods.

Passing 1-D Arrays as arguments to methods

One can pass the 1-D arrays to a method. There are various options like first, you declare and initialize the array separately then pass it to the method. Second, you can declare, initialize and pass the array to the method in a single line of code.

Example 1: Declaring and initializing array first and then pass it to the method as an argument.  

C#

// taking an integer array
// declaring and initializing
// the array
int[] arr = {1, 2, 3, 4};

// passing the array as an
// argument to the method
// Result is the method name
Result(arr);

Example 2: Declaring, initializing, and passing the array to the method in a single line of code.

Result(new int[] {1, 2, 3, 4});

Code: In the below program, we are passing the 1-D array arr to the method Result. The method is static and it will print the array elements which are passed to it. 

C#

// C# program for passing the 1-D
// array to method as argument
using System;

class GFG {

    // declaring a method
    static void Result(int[] arr) {

        // displaying the array elements
        for(int i = 0; i < arr.Length; i++)
        {
            Console.WriteLine("Array Element: "+arr[i]);
        }

    }

    // Main method
    public static void Main() {

        // declaring an array
        // and initializing it
        int[] arr = {1, 2, 3, 4, 5};

        // calling the method
        Result(arr);
    }
}

Output:

Array Element: 1
Array Element: 2
Array Element: 3
Array Element: 4
Array Element: 5

Passing Multi-Dimensional Arrays as arguments to Methods

You can also pass the multidimensional arrays to a method. There are various options like first, you declare and initialize the multi-dimensional array separately then pass it the to the method. Second, you can declare, initialize and pass the array to the method in a single line of code.

Example 1: Declaring and initializing array first and then pass it to the method as an argument.  

C#

// declaring and initializing
// the 2-D array
int[,] arr = { {1, 2, 3, 4}, {5, 6, 7, 8} };

// passing the array as an
// argument to the method
// Result is the method name
Result(arr);

Example 2: Declaring, initializing and passing the 2-D array to the method in a single line of code.

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

Code: In the below program, we are passing an 2-D array arr to the method transpose which gave the transpose of the matrix. GetLength() method is used for the count the total number of elements in a particular dimension. 

C#

// C# program for finding the transpose
// of matrix(2-D array) by using array
// as function arguments
using System;

class GFG {

    // temp is used as temporary variable
    static int temp = 0;


    // passing 2-D array 'arr' as argument
    // to find the transpose of matrix
    static void transpose(int[, ] arr)
    {
        for (int i = 0; i < arr.GetLength(0); i++) {
            for (int j = i; j < arr.GetLength(1); j++) {
                temp = arr[i, j];
                arr[i, j] = arr[j, i];
                arr[j, i] = temp;
            }
        }
    }

    // to display the transposed matrix
    static void displayresult(int[, ] arr)
    {

        Console.WriteLine("Matrix After Transpose: ");

        for (int i = 0; i < arr.GetLength(0); i++) {
            for (int j = 0; j < arr.GetLength(1); j++)
                Console.Write(arr[i, j] + " ");
            Console.WriteLine();
        }
    }

    // Main Method
    static public void Main()
    {
        // declaration of an 2-d array
        int[, ] arr;

        // initializing 2-D array
        // matrix of 4 rows and 4 columns
        arr = new int[4, 4]{ { 1, 2, 3, 4},
                             { 5, 6, 7, 8},
                             {9, 10, 11, 12},
                             {13, 14, 15, 16} };

        Console.WriteLine("Matrix Before Transpose: ");

        for (int i = 0; i < arr.GetLength(0); i++)
        {
            for (int j = 0; j < arr.GetLength(1); j++)
                Console.Write(arr[i, j] + " ");
            Console.WriteLine();
        }

        Console.WriteLine();

        // calling transpose method
        transpose(arr);

        // calling displayresult method
        // to display the result
        displayresult(arr);
    }
}

Output:

Matrix Before Transpose: 
1 2 3 4 
5 6 7 8 
9 10 11 12 
13 14 15 16 

Matrix After Transpose: 
1 5 9 13 
2 6 10 14 
3 7 11 15 
4 8 12 16