Extract rightmost `n` characters from a string in C#

This post will discuss how to extract rightmost n characters from a string in C#.

For example, if the string is ABC1234 and n = 4, the solution should give substring 1234.

Here’s a utility method that shows how to implement this with the String.Substring() method.

using System;

public static class Extensions

{

public static string Right(this string str, int n) {

return str.Substring(str.Length - n);

}

public class Example

{

public static void Main()

{

string str = "Techie Delight";

int n = 7;

string substr = str.Right(n);

Console.WriteLine(substr);

}

Output: Delight

Download Run Code

The above approach will throw an ArgumentOutOfRangeException when the string’s length is less than the total number of characters required. The following code example demonstrates how to handle this:

using System;

public static class Extensions

{

public static string Right(this string str, int n)

{

if (n > str.Length) {

return str;

}

return str.Substring(str.Length - n);

}

public class Example

{

public static void Main()

{

string str = "Techie Delight";

int n = 7;

string substr = str.Right(n);

Console.WriteLine(substr);

}

Output: Delight

Download Run Code

Here’s another alternative syntax that handles the case when string length is less than the total number of characters.

using System;

public static class Extensions

{

public static string Right(this string str, int n) {

return str.Substring(str.Length < n ? 0 : (str.Length - n));

}

public class Example

{

public static void Main()

{

string str = "Techie Delight";

int n = 7;

string substr = str.Right(n);

Console.WriteLine(substr);

}

Output: Delight

Download Run Code

That’s all about extracting rightmost n characters from a string in C#.