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StringBuilder.Replace Method (String, String, Int32, Int32)

 

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)

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 null.

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.

Exception Condition
ArgumentNullException

oldValue is null.

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 MaxCapacity.

This method performs an ordinal, case-sensitive comparison to identify occurrences of oldValue in the specified substring. If newValue is nullorString.Empty, all occurrences of oldValue are removed.

The following example demonstrates the Replace method.

using System;
using System.Text;

class Sample 
{
    public static void Main() 
    {
//                0----+----1----+----2----+----3----+----4---
//                01234567890123456789012345678901234567890123
    string str = "The quick br!wn d#g jumps #ver the lazy cat.";
    StringBuilder sb = new StringBuilder(str);

    Console.WriteLine();
    Console.WriteLine("StringBuilder.Replace method");
    Console.WriteLine();

    Console.WriteLine("Original value:");
    Show(sb);

    sb.Replace('#', '!', 15, 29);        // Some '#' -> '!'
    Show(sb);
    sb.Replace('!', 'o');                // All '!' -> 'o'
    Show(sb);
    sb.Replace("cat", "dog");            // All "cat" -> "dog"
    Show(sb);
    sb.Replace("dog", "fox", 15, 20);    // Some "dog" -> "fox"

    Console.WriteLine("Final value:");
    Show(sb);
    }

    public static void Show(StringBuilder sbs)
    {
    string rule1 = "0----+----1----+----2----+----3----+----4---";
    string rule2 = "01234567890123456789012345678901234567890123";

    Console.WriteLine(rule1);
    Console.WriteLine(rule2);
    Console.WriteLine("{0}", sbs.ToString());
    Console.WriteLine();
    }
}
/*
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.

*/

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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