C#: Create a new string taking the first 3 characters of a given string and return the string with the 3 characters added at both the front and back

Last update on June 25 2025 13:04:09 (UTC/GMT +8 hours)

First Three Characters Front and Back

Write a C# Sharp program to create a string taking the first 3 characters of a given string. Return the string with the 3 characters added at both the front and back. If the given string length is less than 3, use whatever characters are there.

Visual Presentation:

Sample Solution:

C# Sharp Code:

using System;

// Namespace declaration
namespace exercises
{
    // Class declaration
    class Program
    {
        // Main method - entry point of the program
        static void Main(string[] args)
        {
            // Calling the 'test' method with different strings and displaying the returned values
            Console.WriteLine(test("Python")); // Output: PytPythonPyt
            Console.WriteLine(test("JS"));     // Output: JSJSJS
            Console.WriteLine(test("Code"));   // Output: CodCodeCod
            Console.ReadLine();                // Keeping the console window open
        }

        // Method to process a string based on its length
        public static string test(String str)
        {
            // If the length of the string is less than 3, concatenate the string with itself twice
            if (str.Length < 3)
            {
                return str + str + str;
            }
            else
            {
                // If the length of the string is 3 or more, extract the first three characters
                string front = str.Substring(0, 3);
                // Concatenate the first three characters, the original string, and the first three characters again
                return front + str + front;
            }
        }
    }
}

Sample Output:

PytPythonPyt
JSJSJS
CodCodeCod

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C# program to create a new string by taking the last 3 characters and adding them at both front and back.
• Write a C# program to surround a string with its first 3 and last 3 characters alternately.
• Write a C# program to generate a new string that repeats the first 2 characters at the front and first 3 characters at the back.
• Write a C# program to insert the first three characters of a string after every third character in the string.

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