StringBuilder

Reverse String
Reverse String in C# 
using System.Text;

public static class ReverseString
{
    public static string Reverse(string input)
    {
        var chars = new StringBuilder();
        for (var i = input.Length - 1; i >= 0; i--)
        {
            chars.Append(input[i]);
        }
        return chars.ToString();
    }
}

Strings can also be created using the StringBuilder class. The purpose of this class is to efficiently and incrementally build a string.

Note

A StringBuilder is often overkill when used to create short strings, but can be very useful to create larger strings.

The first step is to create a StringBuilder. We then use a for-loop to walk through the string's characters in reverse order, appending them to the StringBuilder via its Append() method.

Finally, we return the reversed string by calling the ToString() method on the StringBuilder instance.

Performance

If you're interested in how this approach's performance compares to other approaches, check the performance approach.

11th Dec 2024 · Found it useful?

Other Approaches to Reverse String in C#

Other ways our community solved this exercise
var chars = input.ToCharArray();
Array.Reverse(chars);
return new string(chars);
Array.Reverse

Use Array.Reverse to reverse a string. 

return new string(input.Reverse().ToArray());
LINQ

Use LINQ to concisely reverse a string. 

Span<char> chars = stackalloc char[input.Length];
for (var i = 0; i < input.Length; i++)
{
    chars[input.Length - 1 - i] = input[i];
}
return new string(chars);
Span<T>

Use Span<T> and stack allocation for hyper-optimized string reversal.