19 Arrays

we will discuss..

1. Array

2. Multidimensional Array

3. Jagged arrays 

4. Passing arrays to function  

5. Param arrays 

Array: 

An array are used to stores fixed-size number of element values of the same type. Array is used to store a collection of data same type stored at contiguous memory location, array index starts from 0. We can store only fixed set of elements in C# array.

Different ways Array Declaration and Initialization

To create an array of string, you could write:

1. string[]name="chandan","amit","biplob","prakash","gaurav","marry"};

To create an array of integers, you could write:

2. int [] num ={ 10, 14, 24, 34 }; or int[] num = new int[]{ 10, 14, 24, 34 };

3. int [] num = new int[5];//creating array  

     You cannot place square brackets after the identifier.

     int arr[] = new int[5];//compile time error

4.   string[] str1;

      str1 = {"chandan","amit","biplob","prakash" }; // error : wrong initialization of an array

Multidimensional Array:

multidimensional array is also called as rectangular arrays in C#. It can be support either two dimensional or three dimensional.Multidimensional Arrays can be declared by specifying the data type of an elements followed by the square brackets [] with comma (,) separator inside the square brackets..The data is stored in tabular form (row * column) which is also known as matrix. which has x number of row and y number of column. 

Following way to creating two or three dimensional arrays in c# programming language.


int[,] arr=new int[3,3];//declaration of 2D array 

// Two-dimensional array.
1.  int[,] arrayTwoD = new int[,]  { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 } };

// The same array with dimensions specified.
2.  int[,] arrayTwoDa = new int[4, 2] { { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 } };

// A similar array with string elements.
3.  string[,] arrayTwoDb = new string[3, 2] { { "one", "two" }, { "three", "four" },
                                        { "five", "six" } };

public class  2Darray 
{
    public static void Main(string[] args)  
    {  
        int [,] arr = new int [3,3]; //declaration of 2D array  
        arr [0,1] = 10; //initialization  
        arr [1,2] = 20;  
        arr [2,0] = 30;  

        for(int i=0;i<3;i++){  
            for(int j=0;j<3;j++){  
                Console.Write(arr[i,j]+" ");  
            }  
            Console.WriteLine(); //new line at each row  
        }
      Console.ReadLine();  
    }  
}  

Output

0 10 0
0 0 20
30 0 0

int[,,] arr=new int[3,3,3];//declaration of 3D array  

public class  2Darray 

{

    public static void Main(string[] args)  

    {  
        int [, ] arr = { { 10, 20, 30 }, { 40, 50, 60 }, { 70, 80, 90 } };//declaration and initialization  


       

        for(int i=0;i<3;i++){  

            for(int j=0;j<3;j++){  

                Console.Write(arr[i, j]+" ");  

            }  

            Console.WriteLine(); //new line at each row  

        }  

       Console.ReadLine();

    }  



}  






Output

10  20  30

40  50  60

70  80  90

How can you declare array ?











int[ , ] arr;

arr = new int[ , ] { { 1, 2}, {3, 4}, {5, 6} }; //success

arr = {{1,2}, {3,4},{4,5},{6,7}}; //Error