What is array in C#

An array store fixed-size sequential collection of elements of the same datatype. It is used to store the collection of data of same data type at contiguous memory locations.

Declaration of array –

Datatype [ ] arrayname;

Datatype specify the data of elements in the array.

[ ] specify the size of the array.

And arrayname is the name of array.

Initializing an Array -

An array is the reference type so we need new keyword to create the instance of the array. For example –

double d= new double [10];

Assigning value to an Array –

We can assign the value to an array by using the index number. For example –

double d= new double [10];

d[0]=100;

we can also assign the value to an array at the time of declaration –

double[ ] d={10,15,20,25,30}

We can also create and initialize the array as the following ways

int[ ] mark=new int[5] {20,21,22,23,29}

or

int[] mark=new int[ ] {22,24,26,28,29}

The Example of the array is given below:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication18
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] n = new int[10];
            int i, j;
            for (i = 0; i < 10; i++)
            {
                n[i] = i + 10;
            }
            for (j = 0; j < 10; j++)
            {
                Console.WriteLine("index[{0}] = {1}", j, n[j]);
            }
            Console.ReadKey();
        }
    }
}
 

Output - 

Following are the some important concept related to the array.

Multi-dimensional arrays – C# support multi-dimensional arrays. It is also called two dimensional arrays.

Jagged arrays – The array of array is also jagged arrays.

Passing arrays to functions – We can pass a function to an array by specifying the array name without an index.

Param arrays – Param arrays is used to pass unknown number of parameter to a function

The array class – The array class provides the various properties and methods by define system name space.