Replace Method (Char, Char)
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String.Replace Method (Char, Char)


Returns a new string in which all occurrences of a specified Unicode character in this instance are replaced with another specified Unicode character.

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

public string Replace(
	char oldChar,
	char newChar


Type: System.Char

The Unicode character to be replaced.

Type: System.Char

The Unicode character to replace all occurrences of oldChar.

Return Value

Type: System.String

A string that is equivalent to this instance except that all instances of oldChar are replaced with newChar. If oldChar is not found in the current instance, the method returns the current instance unchanged.

This method performs an ordinal (case-sensitive and culture-insensitive) search to find oldChar.


This method does not modify the value of the current instance. Instead, it returns a new string in which all occurrences of oldChar are replaced by newChar.

Because this method returns the modified string, you can chain together successive calls to the Replace method to perform multiple replacements on the original string. Method calls are executed from left to right. The following example provides an illustration.

using System;

public class Example
   public static void Main()
      String s = new String('a', 3);
      Console.WriteLine("The initial string: '{0}'", s);
      s = s.Replace('a', 'b').Replace('b', 'c').Replace('c', 'd');
      Console.WriteLine("The final string: '{0}'", s);
// The example displays the following output:
//       The initial string: 'aaa'
//       The final string: 'ddd'

The following example creates a comma separated value list by substituting commas for the blanks between a series of numbers.

using System;

class stringReplace1 {
    public static void Main() {
        String str = "1 2 3 4 5 6 7 8 9";
        Console.WriteLine("Original string: \"{0}\"", str);
        Console.WriteLine("CSV string:      \"{0}\"", str.Replace(' ', ','));
// This example produces the following output:
// Original string: "1 2 3 4 5 6 7 8 9"
// CSV string:      "1,2,3,4,5,6,7,8,9"

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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