Array Class

Definition

public ref class Array abstract : System::Collections::IList, System::Collections::IStructuralComparable, System::Collections::IStructuralEquatable

public ref class Array abstract : ICloneable, System::Collections::IList, System::Collections::IStructuralComparable, System::Collections::IStructuralEquatable

public ref class Array abstract : ICloneable, System::Collections::IList

public abstract class Array : System.Collections.IList, System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable

public abstract class Array : ICloneable, System.Collections.IList, System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable

[System.Serializable]
public abstract class Array : ICloneable, System.Collections.IList

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class Array : ICloneable, System.Collections.IList

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class Array : ICloneable, System.Collections.IList, System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable

type Array = class
    interface ICollection
    interface IEnumerable
    interface IList
    interface IStructuralComparable
    interface IStructuralEquatable

type Array = class
    interface ICollection
    interface IEnumerable
    interface IList
    interface IStructuralComparable
    interface IStructuralEquatable
    interface ICloneable

[<System.Serializable>]
type Array = class
    interface ICloneable
    interface IList
    interface ICollection
    interface IEnumerable

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type Array = class
    interface ICloneable
    interface IList
    interface ICollection
    interface IEnumerable

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type Array = class
    interface ICloneable
    interface IList
    interface ICollection
    interface IEnumerable
    interface IStructuralComparable
    interface IStructuralEquatable

type Array = class
    interface IList
    interface ICollection
    interface IEnumerable
    interface IStructuralComparable
    interface IStructuralEquatable

Public MustInherit Class Array
Implements IList, IStructuralComparable, IStructuralEquatable

Public MustInherit Class Array
Implements ICloneable, IList, IStructuralComparable, IStructuralEquatable

Public MustInherit Class Array
Implements ICloneable, IList

Inheritance

Object

Array

Attributes

SerializableAttribute ComVisibleAttribute

Implements

ICollection IEnumerable IList IStructuralComparable IStructuralEquatable ICloneable

Examples

The following code example shows how Array.Copy copies elements between an array of type integer and an array of type Object.

open System

let printValues myArr =
    for i in myArr do
        printf $"\t{i}"
    printfn ""

// Creates and initializes a new integer array and a new Object array.
let myIntArray = [| 1..5 |]
let myObjArray = [| 26..30 |]

// Prints the initial values of both arrays.
printfn "Initially,"
printf "integer array:"
printValues myIntArray
printfn "Object array: "
printValues myObjArray

// Copies the first two elements from the integer array to the Object array.
Array.Copy(myIntArray, myObjArray, 2)

// Prints the values of the modified arrays.
printfn "\nAfter copying the first two elements of the integer array to the Object array,"
printf "integer array:"
printValues myIntArray
printf"Object array: "
printValues myObjArray

// Copies the last two elements from the Object array to the integer array.
Array.Copy(myObjArray, myObjArray.GetUpperBound 0 - 1, myIntArray, myIntArray.GetUpperBound 0 - 1, 2)

// Prints the values of the modified arrays.
printfn $"\nAfter copying the last two elements of the Object array to the integer array,"
printf "integer array:"
printValues myIntArray
printf "Object array: "
printValues myObjArray


// This code produces the following output.
//     Initially,
//     integer array:  1       2       3       4       5
//     Object array:   26      27      28      29      30
//     
//     After copying the first two elements of the integer array to the Object array,
//     integer array:  1       2       3       4       5
//     Object array:   1       2       28      29      30
//     
//     After copying the last two elements of the Object array to the integer array,
//     integer array:  1       2       3       29      30
//     Object array:   1       2       28      29      30

using System;
public class SamplesArray
{

    public static void Main()
    {

        // Creates and initializes a new integer array and a new Object array.
        int[] myIntArray = new int[5] { 1, 2, 3, 4, 5 };
        Object[] myObjArray = new Object[5] { 26, 27, 28, 29, 30 };

        // Prints the initial values of both arrays.
        Console.WriteLine("Initially,");
        Console.Write("integer array:");
        PrintValues(myIntArray);
        Console.Write("Object array: ");
        PrintValues(myObjArray);

        // Copies the first two elements from the integer array to the Object array.
        System.Array.Copy(myIntArray, myObjArray, 2);

        // Prints the values of the modified arrays.
        Console.WriteLine("\nAfter copying the first two elements of the integer array to the Object array,");
        Console.Write("integer array:");
        PrintValues(myIntArray);
        Console.Write("Object array: ");
        PrintValues(myObjArray);

        // Copies the last two elements from the Object array to the integer array.
        System.Array.Copy(myObjArray, myObjArray.GetUpperBound(0) - 1, myIntArray, myIntArray.GetUpperBound(0) - 1, 2);

        // Prints the values of the modified arrays.
        Console.WriteLine("\nAfter copying the last two elements of the Object array to the integer array,");
        Console.Write("integer array:");
        PrintValues(myIntArray);
        Console.Write("Object array: ");
        PrintValues(myObjArray);
    }

    public static void PrintValues(Object[] myArr)
    {
        foreach (Object i in myArr)
        {
            Console.Write("\t{0}", i);
        }
        Console.WriteLine();
    }

    public static void PrintValues(int[] myArr)
    {
        foreach (int i in myArr)
        {
            Console.Write("\t{0}", i);
        }
        Console.WriteLine();
    }
}
/*
This code produces the following output.

Initially,
integer array:  1       2       3       4       5
Object array:   26      27      28      29      30

After copying the first two elements of the integer array to the Object array,
integer array:  1       2       3       4       5
Object array:   1       2       28      29      30

After copying the last two elements of the Object array to the integer array,
integer array:  1       2       3       29      30
Object array:   1       2       28      29      30
*/

Public Class SamplesArray

    Public Shared Sub Main()

        ' Creates and initializes a new integer array and a new Object array.
        Dim myIntArray() As Integer = {1, 2, 3, 4, 5}
        Dim myObjArray() As Object = {26, 27, 28, 29, 30}

        ' Prints the initial values of both arrays.
        Console.WriteLine("Initially:")
        Console.Write("integer array:")
        PrintValues(myIntArray)
        Console.Write("Object array: ")
        PrintValues(myObjArray)

        ' Copies the first two elements from the integer array to the Object array.
        System.Array.Copy(myIntArray, myObjArray, 2)

        ' Prints the values of the modified arrays.
        Console.WriteLine(ControlChars.NewLine + "After copying the first two" _
           + " elements of the integer array to the Object array:")
        Console.Write("integer array:")
        PrintValues(myIntArray)
        Console.Write("Object array: ")
        PrintValues(myObjArray)

        ' Copies the last two elements from the Object array to the integer array.
        System.Array.Copy(myObjArray, myObjArray.GetUpperBound(0) - 1, myIntArray,
           myIntArray.GetUpperBound(0) - 1, 2)

        ' Prints the values of the modified arrays.
        Console.WriteLine(ControlChars.NewLine + "After copying the last two" _
           + " elements of the Object array to the integer array:")
        Console.Write("integer array:")
        PrintValues(myIntArray)
        Console.Write("Object array: ")
        PrintValues(myObjArray)
    End Sub

    Public Overloads Shared Sub PrintValues(myArr() As Object)
        Dim i As Object
        For Each i In myArr
            Console.Write(ControlChars.Tab + "{0}", i)
        Next i
        Console.WriteLine()
    End Sub

    Public Overloads Shared Sub PrintValues(myArr() As Integer)
        Dim i As Integer
        For Each i In myArr
            Console.Write(ControlChars.Tab + "{0}", i)
        Next i
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' Initially:
' integer array:  1       2       3       4       5
' Object array:   26      27      28      29      30
' 
' After copying the first two elements of the integer array to the Object array:
' integer array:  1       2       3       4       5
' Object array:   1       2       28      29      30
' 
' After copying the last two elements of the Object array to the integer array:
' integer array:  1       2       3       29      30
' Object array:   1       2       28      29      30

The following code example creates and initializes an Array and displays its properties and its elements.

open System

let printValues (myArray: Array) =
    let mutable i = 0
    let cols = myArray.GetLength(myArray.Rank - 1)
    for item in myArray do
        if i < cols then
            i <- i + 1
        else
            printfn ""
            i <- 1;
        printf $"\t{item}"
    printfn ""

// Creates and initializes a new three-dimensional Array of type int.
let myArr = Array.CreateInstance(typeof<int>, 2, 3, 4)
for i = myArr.GetLowerBound 0 to myArr.GetUpperBound 0 do
    for j = myArr.GetLowerBound 1 to myArr.GetUpperBound 1 do
        for k = myArr.GetLowerBound 2 to myArr.GetUpperBound 2 do
            myArr.SetValue(i * 100 + j * 10 + k, i, j, k)

// Displays the properties of the Array.
printfn $"The Array has {myArr.Rank} dimension(s) and a total of {myArr.Length} elements."
printfn $"\tLength\tLower\tUpper"

for i = 0 to myArr.Rank - 1 do
    printf $"{i}:\t{myArr.GetLength i}"
    printfn $"\t{myArr.GetLowerBound i}\t{myArr.GetUpperBound i}"

// Displays the contents of the Array.
printfn "The Array contains the following values:"
printValues myArr

// This code produces the following output.
// The Array has 3 dimension(s) and a total of 24 elements.
//     Length    Lower    Upper
// 0:  2    0    1
// 1:  3    0    2
// 2:  4    0    3
//
// The Array contains the following values:
//    0      1      2      3
//    10     11     12     13
//    20     21     22     23
//    100    101    102    103
//    110    111    112    113
//    120    121    122    123

// Creates and initializes a new three-dimensional Array of type int.
Array myArr = Array.CreateInstance(typeof(int), 2, 3, 4);
for (int i = myArr.GetLowerBound(0); i <= myArr.GetUpperBound(0); i++)
{
    for (int j = myArr.GetLowerBound(1); j <= myArr.GetUpperBound(1); j++)
    {
        for (int k = myArr.GetLowerBound(2); k <= myArr.GetUpperBound(2); k++)
        {
            myArr.SetValue((i * 100) + (j * 10) + k, i, j, k);
        }
    }
}

// Displays the properties of the Array.
Console.WriteLine("The Array has {0} dimension(s) and a total of {1} elements.", myArr.Rank, myArr.Length);
Console.WriteLine("\tLength\tLower\tUpper");
for (int i = 0; i < myArr.Rank; i++)
{
    Console.Write("{0}:\t{1}", i, myArr.GetLength(i));
    Console.WriteLine("\t{0}\t{1}", myArr.GetLowerBound(i), myArr.GetUpperBound(i));
}

// Displays the contents of the Array.
Console.WriteLine("The Array contains the following values:");
PrintValues(myArr);

void PrintValues(Array myArray)
{
    System.Collections.IEnumerator myEnumerator = myArray.GetEnumerator();
    int i = 0;
    int cols = myArray.GetLength(myArray.Rank - 1);
    while (myEnumerator.MoveNext())
    {
        if (i < cols)
        {
            i++;
        }
        else
        {
            Console.WriteLine();
            i = 1;
        }
        Console.Write("\t{0}", myEnumerator.Current);
    }
    Console.WriteLine();
}
// This code produces the following output.

// The Array has 3 dimension(s) and a total of 24 elements.
//     Length    Lower    Upper
// 0:  2    0    1
// 1:  3    0    2
// 2:  4    0    3
//
// The Array contains the following values:
//    0      1      2      3
//    10     11     12     13
//    20     21     22     23
//    100    101    102    103
//    110    111    112    113
//    120    121    122    123

Public Class SamplesArray2

    Public Shared Sub Main()

        ' Creates and initializes a new three-dimensional Array of
        ' type Int32.
        Dim myArr As Array = Array.CreateInstance(GetType(Int32), 2, 3, 4)
        Dim i As Integer
        For i = myArr.GetLowerBound(0) To myArr.GetUpperBound(0)
            Dim j As Integer
            For j = myArr.GetLowerBound(1) To myArr.GetUpperBound(1)
                Dim k As Integer
                For k = myArr.GetLowerBound(2) To myArr.GetUpperBound(2)
                    myArr.SetValue(i * 100 + j * 10 + k, i, j, k)
                Next k
            Next j
        Next i ' Displays the properties of the Array.
        Console.WriteLine("The Array has {0} dimension(s) and a " _
           + "total of {1} elements.", myArr.Rank, myArr.Length)
        Console.WriteLine(ControlChars.Tab + "Length" + ControlChars.Tab _
           + "Lower" + ControlChars.Tab + "Upper")
        For i = 0 To myArr.Rank - 1
            Console.Write("{0}:" + ControlChars.Tab + "{1}", i,
               myArr.GetLength(i))
            Console.WriteLine(ControlChars.Tab + "{0}" + ControlChars.Tab _
               + "{1}", myArr.GetLowerBound(i), myArr.GetUpperBound(i))
        Next i

        ' Displays the contents of the Array.
        Console.WriteLine("The Array contains the following values:")
        PrintValues(myArr)
    End Sub

    Public Shared Sub PrintValues(myArr As Array)
        Dim myEnumerator As System.Collections.IEnumerator =
           myArr.GetEnumerator()
        Dim i As Integer = 0
        Dim cols As Integer = myArr.GetLength(myArr.Rank - 1)
        While myEnumerator.MoveNext()
            If i < cols Then
                i += 1
            Else
                Console.WriteLine()
                i = 1
            End If
            Console.Write(ControlChars.Tab + "{0}", myEnumerator.Current)
        End While
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' The Array has 3 dimension(s) and a total of 24 elements.
'     Length    Lower    Upper
' 0:    2    0    1
' 1:    3    0    2
' 2:    4    0    3
' The Array contains the following values:
'     0    1    2    3
'     10    11    12    13
'     20    21    22    23
'     100    101    102    103
'     110    111    112    113
'     120    121    122    123

Remarks

The Array class is not part of the System.Collections namespaces. However, it is still considered a collection because it is based on the IList interface.

The Array class is the base class for language implementations that support arrays. However, only the system and compilers can derive explicitly from the Array class. Users should employ the array constructs provided by the language.

An element is a value in an Array. The length of an Array is the total number of elements it can contain. The lower bound of an Array is the index of its first element. An Array can have any lower bound, but it has a lower bound of zero by default. A different lower bound can be defined when creating an instance of the Array class using CreateInstance. A multidimensional Array can have different bounds for each dimension. An array can have a maximum of 32 dimensions.

Unlike the classes in the System.Collections namespaces, Array has a fixed capacity. To increase the capacity, you must create a new Array object with the required capacity, copy the elements from the old Array object to the new one, and delete the old Array.

The array size is limited to a total of 4 billion elements, and to a maximum index of 0X7FEFFFFF in any given dimension (0X7FFFFFC7 for byte arrays and arrays of single-byte structures).

.NET Framework only: By default, the maximum size of an Array is 2 gigabytes (GB). In a 64-bit environment, you can avoid the size restriction by setting the enabled attribute of the gcAllowVeryLargeObjects configuration element to true in the run-time environment.

Single-dimensional arrays implement the System.Collections.Generic.IList<T>, System.Collections.Generic.ICollection<T>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IReadOnlyList<T>, and System.Collections.Generic.IReadOnlyCollection<T> generic interfaces. The implementations are provided to arrays at runtime, and as a result, the generic interfaces do not appear in the declaration syntax for the Array class. In addition, there are no reference topics for interface members that are accessible only by casting an array to the generic interface type (explicit interface implementations). The key thing to be aware of when you cast an array to one of these interfaces is that members that add, insert, or remove elements throw NotSupportedException.

Type objects provide information about array type declarations. Array objects with the same array type share the same Type object.

Type.IsArray and Type.GetElementType might not return the expected results with Array because if an array is cast to the type Array, the result is an object, not an array. That is, typeof(System.Array).IsArray returns false, and typeof(System.Array).GetElementType returns null.

The Array.Copy method copies elements not only between arrays of the same type but also between standard arrays of different types; it handles type casting automatically.

Some methods, such as CreateInstance, Copy, CopyTo, GetValue, and SetValue, provide overloads that accept 64-bit integers as parameters to accommodate large capacity arrays. LongLength and GetLongLength return 64-bit integers indicating the length of the array.

The Array is not guaranteed to be sorted. You must sort the Array prior to performing operations (such as BinarySearch) that require the Array to be sorted.

Using an Array object of pointers in native code is not supported and will throw a NotSupportedException for several methods.