How to Replace a Substring in a String using Regular Expression in C# - Step by Step Examples

How to Replace a Substring in a String using Regular Expression in C# ?

Answer

To replace all occurrences of a substring in a string using regular expression in C#, you can use the Regex.Replace method.

✐ Examples

1 Replace Substring "Hello" with "Hi"

In this example,

We create a string named str.
We define a regex pattern matching "Hello".
We replace all occurrences of the pattern in str with "Hi" using Regex.Replace method.
Finally, we print the modified string.

C# Program

using System;
using System.Text.RegularExpressions;

public class Program
{
	public static void Main()
	{
		string str = "Hello World Hello";
		string newStr = Regex.Replace(str, "Hello", "Hi");
		Console.WriteLine(newStr);
	}
}

Output

Hi World Hi

2 Replace Digits with 'Y'

In this example,

We create a string named str.
We define a regex pattern matching digits (\d).
We replace all occurrences of the pattern in str with 'Y' using Regex.Replace method.
Finally, we print the modified string.

C# Program

using System;
using System.Text.RegularExpressions;

public class Program
{
	public static void Main()
	{
		string str = "Hello123World789";
		string newStr = Regex.Replace(str, "\d", "Y");
		Console.WriteLine(newStr);
	}
}

Output

HelloYYYWorldYYY

Summary

In this tutorial, we learned How to Replace a Substring in a String using Regular Expression in C# language with well detailed examples.

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How to Replace a Substring in a String using Regular Expression in C# - Step by Step Examples

How to Replace a Substring in a String using Regular Expression in C# ?

Answer

✐ Examples

1 Replace Substring "Hello" with "Hi"

C# Program

Output

2 Replace Digits with 'Y'

C# Program

Output

Summary

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