Array.Clear Method
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Sets a range of elements in the Array to zero, to false, or to nulla null reference (Nothing in Visual Basic), depending on the element type.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
<SecuritySafeCriticalAttribute> _
Public Shared Sub Clear ( _
array As Array, _
index As Integer, _
length As Integer _
)
[SecuritySafeCriticalAttribute]
public static void Clear(
Array array,
int index,
int length
)
Parameters
- array
Type: System.Array
The Array whose elements need to be cleared.
- index
Type: System.Int32
The starting index of the range of elements to clear.
- length
Type: System.Int32
The number of elements to clear.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentNullException | array is nulla null reference (Nothing in Visual Basic). |
| IndexOutOfRangeException | index is less than the lower bound of array. -or- length is less than zero. -or- The sum of index and length is greater than the size of the Array. |
Remarks
Reference-type elements are set to nulla null reference (Nothing in Visual Basic). Boolean-type elements are set to false. Other value-type elements are set to zero.
The range of cleared elements wrap from row to row in a multi-dimensional array.
This method only clears the values of the elements; it does not delete the elements themselves. An Array has a fixed size; therefore, elements cannot be added or removed.
This method is an O(n) operation, where n is length.
Examples
The following example demonstrates the use of the Clear method with multi-dimensional arrays.
' Visual Basic .NET versions 1.0 and 1.1
Module Example
Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
outputBlock.Text &= vbLf & "One dimension (Rank=1):" & vbCrLf
Dim numbers1() As Integer = {1, 2, 3, 4, 5, 6, 7, 8, 9}
For i As Integer = 0 To 8
outputBlock.Text += String.Format("{0} ", numbers1(i))
Next i
outputBlock.Text &= vbCrLf
outputBlock.Text += String.Format(vbLf & "Array.Clear(numbers1, 2, 5)") & vbCrLf
Array.Clear(numbers1, 2, 5)
For i As Integer = 0 To 8
outputBlock.Text += String.Format("{0} ", numbers1(i))
Next i
outputBlock.Text &= vbCrLf
outputBlock.Text &= vbLf & "Two dimensions (Rank=2):" & vbCrLf
Dim numbers2(,) As Integer = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}
For i As Integer = 0 To 2
For j As Integer = 0 To 2
outputBlock.Text += String.Format("{0} ", numbers2(i, j))
Next j
outputBlock.Text &= vbCrLf
Next i
outputBlock.Text += String.Format(vbLf & "Array.Clear(numbers2, 2, 5)") & vbCrLf
Array.Clear(numbers2, 2, 5)
For i As Integer = 0 To 2
For j As Integer = 0 To 2
outputBlock.Text += String.Format("{0} ", numbers2(i, j))
Next j
outputBlock.Text &= vbCrLf
Next i
outputBlock.Text &= vbLf & "Three dimensions (Rank=3):" & vbCrLf
Dim numbers3(,,) As Integer = {{{1, 2}, {3, 4}}, _
{{5, 6}, {7, 8}}, _
{{9, 10}, {11, 12}}}
For i As Integer = 0 To 1
For j As Integer = 0 To 1
For k As Integer = 0 To 1
outputBlock.Text += String.Format("{0} ", numbers3(i, j, k))
Next k
outputBlock.Text &= vbCrLf
Next j
outputBlock.Text &= vbCrLf
Next i
outputBlock.Text += String.Format("Array.Clear(numbers3, 2, 5)") & vbCrLf
Array.Clear(numbers3, 2, 5)
For i As Integer = 0 To 1
For j As Integer = 0 To 1
For k As Integer = 0 To 1
outputBlock.Text += String.Format("{0} ", numbers3(i, j, k))
Next k
outputBlock.Text &= vbCrLf
Next j
outputBlock.Text &= vbCrLf
Next i
End Sub
End Module
' This code example produces the following output:
'
'One dimension (Rank=1):
'1 2 3 4 5 6 7 8 9
'
'Array.Clear(numbers1, 2, 5)
'1 2 0 0 0 0 0 8 9
'
'Two dimensions (Rank=2):
'1 2 3
'4 5 6
'7 8 9
'
'Array.Clear(numbers2, 2, 5)
'1 2 0
'0 0 0
'0 8 9
'
'Three dimensions (Rank=3):
'1 2
'3 4
'
'5 6
'7 8
'
'Array.Clear(numbers3, 2, 5)
'1 2
'0 0
'
'0 0
'0 8
using System;
class Example
{
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
outputBlock.Text += "One dimension (Rank=1):" + "\n";
int[] numbers1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
for (int i = 0; i < 9; i++)
{
outputBlock.Text += String.Format("{0} ", numbers1[i]);
}
outputBlock.Text += "\n";
outputBlock.Text += "\n";
outputBlock.Text += String.Format("Array.Clear(numbers1, 2, 5)") + "\n";
Array.Clear(numbers1, 2, 5);
for (int i = 0; i < 9; i++)
{
outputBlock.Text += String.Format("{0} ", numbers1[i]);
}
outputBlock.Text += "\n";
outputBlock.Text += "\n";
outputBlock.Text += "Two dimensions (Rank=2):" + "\n";
int[,] numbers2 = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } };
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
outputBlock.Text += String.Format("{0} ", numbers2[i, j]);
}
outputBlock.Text += "\n";
}
outputBlock.Text += "\n";
outputBlock.Text += String.Format("Array.Clear(numbers2, 2, 5)") + "\n";
Array.Clear(numbers2, 2, 5);
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
outputBlock.Text += String.Format("{0} ", numbers2[i, j]);
}
outputBlock.Text += "\n";
}
outputBlock.Text += "Three dimensions (Rank=3):" + "\n";
int[, ,] numbers3 = {{{1, 2}, {3, 4}},
{{5, 6}, {7, 8}},
{{9, 10}, {11, 12}}};
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2; j++)
{
for (int k = 0; k < 2; k++)
{
outputBlock.Text += String.Format("{0} ", numbers3[i, j, k]);
}
outputBlock.Text += "\n";
}
outputBlock.Text += "\n";
}
outputBlock.Text += String.Format("Array.Clear(numbers3, 2, 5)") + "\n";
Array.Clear(numbers3, 2, 5);
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2; j++)
{
for (int k = 0; k < 2; k++)
{
outputBlock.Text += String.Format("{0} ", numbers3[i, j, k]);
}
outputBlock.Text += "\n";
}
outputBlock.Text += "\n";
}
}
}
/* This code example produces the following output:
*
* One dimension (Rank=1):
* 1 2 3 4 5 6 7 8 9
*
* Array.Clear(numbers1, 2, 5)
* 1 2 0 0 0 0 0 8 9
*
* Two dimensions (Rank=2):
* 1 2 3
* 4 5 6
* 7 8 9
*
* Array.Clear(numbers2, 2, 5)
* 1 2 0
* 0 0 0
* 0 8 9
*
* Three dimensions (Rank=3):
* 1 2
* 3 4
*
* 5 6
* 7 8
*
* Array.Clear(numbers3, 2, 5)
* 1 2
* 0 0
*
* 0 0
* 0 8
*/
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0
XNA Framework
Supported in: Xbox 360, Windows Phone OS 7.0
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.