Working With Arrays in C#

Working with Arrays

1            Arrays are reference types and are allocated memory on heap.

2            Every element of an array is automatically initialized to a default value based on its data type.
3            They are always dynamic because we can SET the size of the arrays at runtime.
4            Size of array can never be changed at runtime but we can create a new array with new length and copy the data from old array into new array.
5            Trying to access an element of array with invalid index throws IndexOutofRangeException Exception.
6            All arrays irrespective of their type are by default inherited from System. Array class
7            In C# we can have arrays of arrays and those are referred as Jagged Arrays. Here every element of the first array elements refers to another array and each one of them can be of different length

Single-Dimensional Arrays

int [] myArray = new int [5]; string []myStringArray = new string[5]; When you initialize an array upon declaration, it is possible to use the following shortcuts: int[] myArray = {1, 3, 5, 7, 9}; string[] weekDays = {"Sun", "Sat", "Mon", "Tue"}; It is possible to declare an array variable without initialization, but you must use the new operator when you assign an array to this variable. For example: int[] myArray; myArray = new int[] {1, 3, 5, 7, 9};   // OK myArray = {1, 3, 5, 7, 9};   // Error weekdays = new string[] {“Sunday”, “Monday”, “Tuesday”};

Multi-Dimensional Arrays

int[,] myArray = new int[4,2]; Also, the following declaration creates an array of three dimensions, 4, 2, and 3: int[,,] myArray = new int [4,2,3]; You can initialize the array upon declaration as shown in the following example: int[,] myArray = new  int[,] {{1,2}, {3,4}, {5,6}, {7,8}}; You can also initialize the array without specifying the rank: int[,] myArray = {{1,2}, {3,4}, {5,6}, {7,8}}; If you choose to declare an array variable without initialization, you must use the new operator to assign an array to the variable. For example: int[,] myArray; myArray = new int[,] {{1,2}, {3,4}, {5,6}, {7,8}};   // OK myArray = {{1,2}, {3,4}, {5,6}, {7,8}};   // Error

Program to use arrays:
using System; class Program {     static void Main(string[] args)     {         int[] ar = new int[] { 1, 2, 3, 4 };         Console.WriteLine(ar.Length);         Console.WriteLine(ar.Rank); //Prints Number of Dimensions in array.         foreach (int n in ar)             Console.WriteLine(n);     } }
Code: 3.9	C#

Program: To read a list of numbers separated by space and print the Average of all those numbers.
using System; class ProgramForMaxOfAnyNumbers {     static void Main(string[] args)     {         string str = Console.ReadLine();         string[] ar = str.Split(' ');         int sum = 0;         for (int i = 0; i < ar.Length; i++)         {             sum += int.Parse(ar[i]);             Console.WriteLine(ar[i]);         }         Console.WriteLine("Average: " + 1.0 * sum / ar.Length);     } }
Code: 3.10	C#

Program: To read length and data for an array from keyboard print the same.
using System; class ProgramForMaxOfAnyNumbers {     static void Main()     {         Console.Write("Enter the array length: ");         int n;         n = int.Parse(Console.ReadLine());         int[] ar = new int[n];         for (int i = 0; i < n; i++)         {             Console.Write("Enter the " + i + "th value: ");             ar[i] = int.Parse(Console.ReadLine());         }         for (int i = 0; i < ar.Length; i++)         {             Console.Write(ar[i] + " ");         }     } }
Code: 3.11	C#

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Tricky Question:

LETS SEE WHAT IS THE OUTPUT OF THE FOLLOWING PROGRAM

class Program
{
        static void Main(string[] args)
        {
            int[] mar1, mar2;
            mar1 = new int[] { 1, 2 };
            mar2 = new int[] { 1, 2 };
            Foo(mar1, ref mar2);
            Console.WriteLine(mar1[0] + " " + mar1[1]);
            Console.WriteLine(mar2[0] + " " + mar2[1]);
        }

        static void Foo(int[] ar1, ref int []ar2)

        {
            ar1[0]++;
            ar2[0]++;
        }
}

LETS KEEP THE DISCUSSION ON...
I WOULD REQUEST YOU TO RUN THE PROGRAM FIND THE ANSWER AND POST YOUR COMMENT WITH REASON...

I WILL PROVIDE THE REASON ONCE I HAVE SOME INPUTS HERE....

Loving You All.

Best of Luck.