StringBuilder.Replace Method (String, String, Int32, Int32)
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Replaces, within a substring of this instance, all occurrences of a specified string with another specified string.
Namespace: System.Text
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Function Replace ( _
oldValue As String, _
newValue As String, _
startIndex As Integer, _
count As Integer _
) As StringBuilder
public StringBuilder Replace(
string oldValue,
string newValue,
int startIndex,
int count
)
Parameters
- oldValue
Type: System.String
The string to replace.
- newValue
Type: System.String
The string that replaces oldValue, or nulla null reference (Nothing in Visual Basic).
- startIndex
Type: System.Int32
The position in this instance where the substring begins.
- count
Type: System.Int32
The length of the substring.
Return Value
Type: System.Text.StringBuilder
A reference to this instance with all instances of oldValue replaced by newValue in the range from startIndex to startIndex + count - 1.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentNullException | oldValue is nulla null reference (Nothing in Visual Basic). |
| ArgumentException | The length of oldvalue is zero. |
| ArgumentOutOfRangeException | startIndex or count is less than zero. -or- startIndex plus count indicates a character position not within this instance. -or- Enlarging the value of this instance would exceed its maximum capacity. |
Remarks
The strings to replace are checked on an ordinal basis; that is, the replacement is not culture-aware. If newValue is nulla null reference (Nothing in Visual Basic), all occurrences of oldValue are removed. This method is case-sensitive.
Platform Notes
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Silverlight for Windows Phone
If you call this method when a null character exists in the string, the new string will be truncated at the first null character.
Examples
The following code example demonstrates the Replace method.
Imports System.Text
Class Example
Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
' 0----+----1----+----2----+----3----+----4---
' 01234567890123456789012345678901234567890123
Dim str As String = "The quick br!wn d#g jumps #ver the lazy cat."
Dim sb As New StringBuilder(str)
outputBlock.Text &= vbCrLf
outputBlock.Text &= "StringBuilder.Replace method" & vbCrLf
outputBlock.Text &= vbCrLf
outputBlock.Text &= "Original value:" & vbCrLf
Show(outputBlock, sb)
sb.Replace("#"c, "!"c, 15, 29) ' Some '#' -> '!'
Show(outputBlock, sb)
sb.Replace("!"c, "o"c) ' All '!' -> 'o'
Show(outputBlock, sb)
sb.Replace("cat", "dog") ' All "cat" -> "dog"
Show(outputBlock, sb)
sb.Replace("dog", "fox", 15, 20) ' Some "dog" -> "fox"
outputBlock.Text &= "Final value:" & vbCrLf
Show(outputBlock, sb)
End Sub 'Main
Public Shared Sub Show(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal sbs As StringBuilder)
Dim rule1 As String = "0----+----1----+----2----+----3----+----4---"
Dim rule2 As String = "01234567890123456789012345678901234567890123"
outputBlock.Text &= rule1 & vbCrLf
outputBlock.Text &= rule2 & vbCrLf
outputBlock.Text += String.Format("{0}", sbs.ToString()) & vbCrLf
outputBlock.Text &= vbCrLf
End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'StringBuilder.Replace method
'
'Original value:
'0----+----1----+----2----+----3----+----4---
'01234567890123456789012345678901234567890123
'The quick br!wn d#g jumps #ver the lazy cat.
'
'0----+----1----+----2----+----3----+----4---
'01234567890123456789012345678901234567890123
'The quick br!wn d!g jumps !ver the lazy cat.
'
'0----+----1----+----2----+----3----+----4---
'01234567890123456789012345678901234567890123
'The quick brown dog jumps over the lazy cat.
'
'0----+----1----+----2----+----3----+----4---
'01234567890123456789012345678901234567890123
'The quick brown dog jumps over the lazy dog.
'
'Final value:
'0----+----1----+----2----+----3----+----4---
'01234567890123456789012345678901234567890123
'The quick brown fox jumps over the lazy dog.
'
using System;
using System.Text;
class Example
{
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
// 0----+----1----+----2----+----3----+----4---
// 01234567890123456789012345678901234567890123
string str = "The quick br!wn d#g jumps #ver the lazy cat.";
StringBuilder sb = new StringBuilder(str);
outputBlock.Text += "\n";
outputBlock.Text += "StringBuilder.Replace method" + "\n";
outputBlock.Text += "\n";
outputBlock.Text += "Original value:" + "\n";
Show(outputBlock, sb);
sb.Replace('#', '!', 15, 29); // Some '#' -> '!'
Show(outputBlock, sb);
sb.Replace('!', 'o'); // All '!' -> 'o'
Show(outputBlock, sb);
sb.Replace("cat", "dog"); // All "cat" -> "dog"
Show(outputBlock, sb);
sb.Replace("dog", "fox", 15, 20); // Some "dog" -> "fox"
outputBlock.Text += "Final value:" + "\n";
Show(outputBlock, sb);
}
public static void Show(System.Windows.Controls.TextBlock outputBlock, StringBuilder sbs)
{
string rule1 = "0----+----1----+----2----+----3----+----4---";
string rule2 = "01234567890123456789012345678901234567890123";
outputBlock.Text += rule1 + "\n";
outputBlock.Text += rule2 + "\n";
outputBlock.Text += String.Format("{0}", sbs.ToString()) + "\n";
outputBlock.Text += "\n";
}
}
/*
This example produces the following results:
StringBuilder.Replace method
Original value:
0----+----1----+----2----+----3----+----4---
01234567890123456789012345678901234567890123
The quick br!wn d#g jumps #ver the lazy cat.
0----+----1----+----2----+----3----+----4---
01234567890123456789012345678901234567890123
The quick br!wn d!g jumps !ver the lazy cat.
0----+----1----+----2----+----3----+----4---
01234567890123456789012345678901234567890123
The quick brown dog jumps over the lazy cat.
0----+----1----+----2----+----3----+----4---
01234567890123456789012345678901234567890123
The quick brown dog jumps over the lazy dog.
Final value:
0----+----1----+----2----+----3----+----4---
01234567890123456789012345678901234567890123
The quick brown fox jumps over the lazy dog.
*/
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.