Array.CopyTo Method (Array, Int64)


Copies all the elements of the current one-dimensional array to the specified one-dimensional array starting at the specified destination array index. The index is specified as a 64-bit integer.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

Public Sub CopyTo (
	array As Array,
	index As Long


Type: System.Array

The one-dimensional array that is the destination of the elements copied from the current array.

Type: System.Int64

A 64-bit integer that represents the index in array at which copying begins.

Exception Condition

array is null.


index is outside the range of valid indexes for array.


array is multidimensional.


The number of elements in the source array is greater than the available number of elements from index to the end of the destination array.


The type of the source Array cannot be cast automatically to the type of the destination array.


The source Array is multidimensional.


At least one element in the source Array cannot be cast to the type of destination array.

This method copies all the elements of the current array instance to the array destination array, starting at index index. The array destination array must already have been dimensioned and must have a sufficient number of elements to accommodate the copied elements. Otherwise, the method throws an exception.

This method supports the System.Collections.ICollection interface. If implementing System.Collections.ICollection is not explicitly required, use Copy to avoid an extra indirection.

If this method throws an exception while copying, the state of array is undefined.

This method is an O(n) operation, where n is Length.It performs a shallow copy only.

The following code example shows how to copy an Array to another Array.

Imports System
Imports Microsoft.VisualBasic

Public Class SamplesArray    

    Public Shared Sub Main()

        ' Creates and initializes two new Arrays.
        Dim mySourceArray As Array = Array.CreateInstance(GetType(String), 6)
        mySourceArray.SetValue("three", 0)
        mySourceArray.SetValue("napping", 1)
        mySourceArray.SetValue("cats", 2)
        mySourceArray.SetValue("in", 3)
        mySourceArray.SetValue("the", 4)
        mySourceArray.SetValue("barn", 5)
        Dim myTargetArray As Array = Array.CreateInstance(GetType(String), 15)
        myTargetArray.SetValue("The", 0)
        myTargetArray.SetValue("quick", 1)
        myTargetArray.SetValue("brown", 2)
        myTargetArray.SetValue("fox", 3)
        myTargetArray.SetValue("jumps", 4)
        myTargetArray.SetValue("over", 5)
        myTargetArray.SetValue("the", 6)
        myTargetArray.SetValue("lazy", 7)
        myTargetArray.SetValue("dog", 8)

        ' Displays the values of the Array.
        Console.WriteLine("The target Array contains the following" _
           & "(before and after copying):")
        PrintValues(myTargetArray, " "c)

        ' Copies the source Array to the target Array, starting at index 6.
        mySourceArray.CopyTo(myTargetArray, 6)

        ' Displays the values of the Array.
        PrintValues(myTargetArray, " "c)
    End Sub    

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

' This code produces the following output.
'  The target Array contains the following (before and after copying):
'  The quick brown fox jumps over the lazy dog      
'  The quick brown fox jumps over three napping cats in the barn

The following code example shows how to copy an Array to another Array with a nonzero lower bound. Note that the entire source Array is copied, including empty elements that overwrite existing elements in the target Array.

Public Class SamplesArray2    

    Public Shared Sub Main()
        ' Creates and initializes the source Array.
        Dim myArrayZero As Array = Array.CreateInstance(GetType(String), 3)
        myArrayZero.SetValue("zero", 0)
        myArrayZero.SetValue("one", 1)

        ' Displays the source Array.
        Console.WriteLine("The array with lower bound=0 contains:")

        ' Creates and initializes the target Array.
        Dim myArrLen As Integer() = {4}
        Dim myArrLow As Integer() = {2}
        Dim myArrayTwo As Array = Array.CreateInstance(GetType(String), _
           myArrLen, myArrLow)
        myArrayTwo.SetValue("two", 2)
        myArrayTwo.SetValue("three", 3)
        myArrayTwo.SetValue("four", 4)
        myArrayTwo.SetValue("five", 5)

        ' Displays the target Array.
        Console.WriteLine("The array with lower bound=2 contains:")

        ' Copies from the array with lower bound=0 to the array with lower bound=2.
        myArrayZero.CopyTo(myArrayTwo, 3)

        ' Displays the modified target Array.
        Console.WriteLine(ControlChars.Cr + "After copying to the target array from " _
           + "index 3:")
    End Sub

    Public Shared Sub PrintIndexAndValues(myArray As Array)
        Dim i As Integer
        For i = myArray.GetLowerBound(0) To myArray.GetUpperBound(0)
            Console.WriteLine(ControlChars.Tab + "[{0}]:" + ControlChars.Tab _
               + "{1}", i, myArray.GetValue(i))
        Next i
    End Sub
End Class

' This code produces the following output.
' The array with lower bound=0 contains:
'     [0]:    zero
'     [1]:    one
'     [2]:    
' The array with lower bound=2 contains:
'     [2]:    two
'     [3]:    three
'     [4]:    four
'     [5]:    five
' After copying to the target array from index 3:
'     [2]:    two
'     [3]:    zero
'     [4]:    one
'     [5]: 

.NET Framework
Available since 1.1
Return to top