1.25.1. Declare array #

To declare an array in C #, you can use the following syntax:

datatype[] arrayName;

Among them

• datatype use to specify the type of element stored in the array.

• [ ] specifies the rank (dimension) of the array. Rank specifies the sizeof the array.

• arrayName specifies the name of the array.

For example:

double[] balance;

1.25.2. Initialize array #

Declaring an array does not initialize the array in memory. When you initialize an array variable, you can assign values to the array.

Array is a reference type, so you need to use the new keyword to createan instance of the array.

For example:

double[] balance = new double[10];

1.25.3. Assign values to an array #

You can assign values to a single array element by using index numbers, suchas:

double[] balance = new double[10];
balance[0] = 4500.0;

You can assign values to an array while declaring it, such as:

double[] balance = { 2340.0, 4523.69, 3421.0};

You can also create and initialize an array, such as:

int [] marks = new int[5]  { 99,  98, 92, 97, 95};

In the above cases, you can also omit the size of the array, such as:

int [] marks = new int[]  { 99,  98, 92, 97, 95};

You can also assign an array variable to another target array variable. In this case, the destination and source point to the same memory location:

int [] marks = new int[]  { 99,  98, 92, 97, 95};
int[] score = marks;

When you create an array, the C# compiler implicitly initializes each array element to a default value based on the array type. For example, all elements of the int array are initialized to 0 .

1.25.4. Access array elements #

The element is accessed through the indexed array name. This is achieved by placing the index of the element in square brackets after the array name. For example:

double salary = balance[9];

Here is an example that uses the three concepts mentioned above, namely, declare, assign, and access arrays:

using System;
namespace ArrayApplication
{
   class MyArray
   {
      static void Main(string[] args)
      {
         int []  n = new int[10]; /* n is an array with 10 integers */
         int i,j;


         /* Initialize elements in array n */
         for ( i = 0; i < 10; i++ )
         {
            n[ i ] = i + 100;
         }

         /* Output the value of each array element */
         for (j = 0; j < 10; j++ )
         {
            Console.WriteLine("Element[{0}] = {1}", j, n[j]);
         }
         Console.ReadKey();
      }
   }
}

Element[0] = 100
Element[1] = 101
Element[2] = 102
Element[3] = 103
Element[4] = 104
Element[5] = 105
Element[6] = 106
Element[7] = 107
Element[8] = 108
Element[9] = 109

1.25.5. Use foreach Cycle #

In the previous example, we used a for loop to access each array element. You can also use a foreach statement to traverse the array.

using System;

namespace ArrayApplication
{
   class MyArray
   {
      static void Main(string[] args)
      {
         int []  n = new int[10]; /* n is an array with 10 integers */


         /* initialize elements in array n */
         for ( int i = 0; i < 10; i++ )
         {
            n[i] = i + 100;
         }

         /* Output the value of each array element */
         foreach (int j in n )
         {
            int i = j-100;
            Console.WriteLine("Element[{0}] = {1}", i, j);
         }
         Console.ReadKey();
      }
   }
}

Element[0] = 100
Element[1] = 101
Element[2] = 102
Element[3] = 103
Element[4] = 104
Element[5] = 105
Element[6] = 106
Element[7] = 107
Element[8] = 108
Element[9] = 109

1.25.6. C # array details #

In C #, arrays are very important and you need to know more details. Here are some important array-related concepts that C # programmers must be awareof: