Arrays

Arrays –it’s a set of similar type value that is store sequentially. They can be arranged in three different types like –

1. single dimensional
2. two dimensional
3. Jagged arrays.

In C# arrays can be declared as fixed length or dynamic. Fixed length array can store a predefined number of items while the size of dynamic array increases as you add new items to the array.

Single Dimensional Array – These are array which store the values in the form of a row.

Syntax of defining the 1 D Array -

(Type) [] (name) = new (type) [size];

int [] arr = new int [4];

or

int [] arr ;

arr = new int[5];

or

int [] arr = {list of values};

Program

using System; class SDArray { static void Main() { int[] arr = new int[5]; arr[0]=10;arr[1]=20;arr[2]=30;arr[3]=40;arr[4]=50; for(int i=0;i<5;i++) Console.Write(arr[i] + " "); Console.WriteLine(); foreach(int i in arr) Console.Write(i + " "); } }

foreach loop – As discussed earlier it has been specially designed for processing values of an array or collection for each iteration of the loop one value of the array is assigned to the variable of the loop and returned to us.

In case of a for loop the variable of the loop refers to index of the array whereas in case of the foreach loop it refers to values of the array.

In case of a for loop the loop variable will always be in only whereas in case of a foreach loop the loop variables type depends upon the type of values in the array.

Note – Arrays are reference type because they give us flexibility to declare a array without specifying any size and later the size can be specified, where this flexibility is given only to reference type.

Array Class- It is a predefined class under the system name space which provides a set of methods and properties (variables) which can be applied on an array.

• sort (array)
• reverse (array)
• copy (src, dest , n)
• length

Note- short, reverse, copy is static members. It is declared like as Arr.short etc..

Program

using System; class SDArray2 { static void Main() { int[] arr = {34, 78, 20, 98, 72, 48, 56, 61, 70, 8, 15}; for(int i=0;i Console.Write(arr[i] + " "); Console.WriteLine(); Array.Sort(arr); foreach(int i in arr) Console.Write(i + " "); Console.WriteLine(); Array.Reverse(arr); foreach(int i in arr) Console.Write(i + " "); Console.WriteLine(); int[] brr = new int[10]; Array.Copy(arr, brr, 5); foreach(int i in brr) Console.Write(i + " "); Console.WriteLine(); } }

TWO Dimensional Arrays – These are the arrays which can store values in the form of rows and columns.

(type)[,](name) = new (type)[rows,cols]; int[,]arr = new int[3,4]; or int[,]arr; arr = new int[2,3]; or int[,] = {list of values};

Program