How is an array declared in C#?

To declare an array in C#, you specify the data type followed by square brackets and the array name. Arrays in C# are reference types that store multiple elements of the same data type in a contiguous memory location.

Syntax

Following is the basic syntax for declaring an array −

datatype[] arrayName;

To declare and initialize an array with a specific size −

datatype[] arrayName = new datatype[size];

To declare and initialize an array with values −

datatype[] arrayName = {value1, value2, value3, ...};

Here −

• datatype specifies the type of elements the array will store (int, double, string, etc.).

• [] indicates that this is an array declaration.

• arrayName is the identifier for the array.

• size specifies the number of elements the array can hold.

Using Array Declaration and Initialization

Example

using System;

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

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

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

The output of the above code is −

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

Using Array Literal Initialization

Example

using System;

class Program {
   static void Main() {
      // Array with initial values
      string[] fruits = {"Apple", "Banana", "Orange", "Mango"};
      
      // Another way to initialize
      double[] prices = new double[] {1.5, 2.0, 1.8, 2.5};
      
      Console.WriteLine("Fruits and their prices:");
      for (int i = 0; i < fruits.Length; i++) {
         Console.WriteLine("{0}: ${1}", fruits[i], prices[i]);
      }
   }
}

The output of the above code is −

Fruits and their prices:
Apple: $1.5
Banana: $2
Orange: $1.8
Mango: $2.5

Different Array Declaration Methods

Conclusion

Arrays in C# are declared using the syntax datatype[] arrayName and can be initialized in multiple ways. You can declare an empty array with a specific size using new datatype[size] or initialize it directly with values using array literals for immediate use.