Arrays (C# Programming Guide)

An array is a data structure that contains several variables of the same type. Arrays are declared with a type:

type[] arrayName;

The following examples create single-dimensional, multidimensional, and jagged arrays:

class TestArraysClass
{
 static void Main()
 {
 // Declare a single-dimensional array 
 int[] array1 = new int[5];
 // Declare and set array element values 
 int[] array2 = new int[] { 1, 3, 5, 7, 9 };
 // Alternative syntax 
 int[] array3 = { 1, 2, 3, 4, 5, 6 };
 // Declare a two dimensional array 
 int[,] multiDimensionalArray1 = new int[2, 3];
 // Declare and set array element values 
 int[,] multiDimensionalArray2 = { { 1, 2, 3 }, { 4, 5, 6 } };
 // Declare a jagged array 
 int[][] jaggedArray = new int[6][];
 // Set the values of the first array in the jagged array structure
 jaggedArray[0] = new int[4] { 1, 2, 3, 4 };
 }
}

Array Overview

An array has the following properties:

• An array can be Single-Dimensional, Multidimensional or Jagged.

• The default value of numeric array elements are set to zero, and reference elements are set to null.

• A jagged array is an array of arrays, and therefore its elements are reference types and are initialized to null.

• Arrays are zero indexed: an array with n elements is indexed from 0 to n-1.

• Array elements can be of any type, including an array type.

• Array types are reference types derived from the abstract base type Array. Since this type implements IEnumerable and IEnumerable<T>, you can use foreach iteration on all arrays in C#.

Related Sections

• Arrays as Objects (C# Programming Guide)

• Using foreach with Arrays (C# Programming Guide)

• Passing Arrays as Arguments (C# Programming Guide)

• Passing Arrays Using ref and out (C# Programming Guide)

• Arrays Sample

C# Language Specification

For more information, see the following sections in the C# Language Specification:

• 1.8 Arrays

• 12 Arrays

See Also

Concepts

C# Programming Guide

Array Collection Type

Arrays in the Common Type System

Reference

Collection Classes (C# Programming Guide)

Array Usage Guidelines