4.4.8. A string we can modify: StringBuilder

If we need to modify a text, letter by letter, we can not use a conventional "string", we need to use a "StringBuilder", which allows it but is a bit more complex to handle: we need to allocate space with the command "new" (as we did for Arrays), and they can be converted to a "conventional" string  using "ToString":

/*---------------------------*/

/*  C# Example #44:          */

/*  example44.cs             */

/*                           */

/*  "StringBuilder"          */

/*                           */

/*  Intro to C#,             */

/*    Nacho Cabanes          */

/*---------------------------*/

using System;

using System.Text; // We will use System.Text.StringBuilder

public class Example44

{

  public static void Main()

  {

    StringBuilder modifiedString = new StringBuilder("Hello");

    modifiedString[1] = 'a';

    Console.WriteLine("Modified string: {0}",

      modifiedString);

   

    string usualString;

    usualString = modifiedString.ToString();

    Console.WriteLine("Conventional string obtained from it: {0}",

      usualString);     

  }

}

Suggested exercises:

·       A program that asks for your name, your birth day and your birth month and gather sit all in a string, separating the name of the date with a comma and the day of the month with a slash, like this: "John, born 31/12 ".

·       A hangman game, in which a first user enters the word to guess, the program displays it hidden under dashes (-----) and the program accepts the letters that a second user enters, changing the dashes for the correct letters (for example, a---at-). The game ends when the user finds the right word or he runs out of attempts (8 maximum).