Csharp/C Sharp/Development Class/StringBuilder

Create a StringBuilder which hold 100 characters.

 
 
using System;
using System.Text;
class StringApp {
    static void Main(string[] args) {
        StringBuilder myBuffer = new StringBuilder("My string data");
        Console.WriteLine(myBuffer.Capacity);
        myBuffer.Append(" contains some numerical data: ");
        myBuffer.AppendFormat("{0}, {1}.", 44, 99);
        Console.WriteLine(myBuffer.Capacity);
        Console.WriteLine(myBuffer);
    }
}

illustrates reading and writing string data

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
 /*
  Example15_17.cs illustrates reading and writing string data
*/
using System;
using System.IO;
using System.Text;
public class Example15_17 
{
  public static void Main() 
  {
    // create a new string to work with
    StringBuilder sb = new StringBuilder();
    // use a StringWriter to write data to the string
    StringWriter sw = new StringWriter(sb);
    // write some text to the string
    sw.Write("This is a test of the StringWriter class");
    sw.Close();
    // now open the string for reading
    StringReader sr = new StringReader(sb.ToString());
    // read the entire string into a buffer and display it
    string EntireString;
  
    EntireString = sr.ReadToEnd();
    Console.WriteLine(EntireString);
    // clean up
    sr.Close();
  }
}

Length and Indexer

 
using System;
using System.Text;
class MainClass
{
    public static string ReverseString(string str)
    {
       if (str == null || str.Length <= 1) 
       {
            return str;
       }
       StringBuilder revStr = new StringBuilder(str.Length);

       for (int count = str.Length - 1; count > -1; count--)
       {
           revStr.Append(str[count]);
       }
       return revStr.ToString();
   }
   public static void Main(){
       Console.WriteLine(ReverseString("Madam Im Adam"));
       Console.WriteLine(ReverseString("The quick brown fox jumped over the lazy dog."));
   }
}

Replace char in a StringBuilder object

 
using System;
using System.Collections.Generic;
using System.Text;
class Program {
    static void Main(string[] args) {
        StringBuilder greetingBuilder = new StringBuilder("www.nfex.ru");
        for (int i = (int)"z"; i >= (int)"a"; i--) {
            char old1 = (char)i;
            char new1 = (char)(i + 1);
            greetingBuilder = greetingBuilder.Replace(old1, new1);
        }
        for (int i = (int)"Z"; i >= (int)"A"; i--) {
            char old1 = (char)i;
            char new1 = (char)(i + 1);
            greetingBuilder = greetingBuilder.Replace(old1, new1);
        }
        Console.WriteLine("Encoded:\n" + greetingBuilder.ToString());
    }
}

Replace Char with String

 
using System;
using System.Text;
public class MainClass {
    static String ReplaceCharString(String s, char c1, String s2) {
        StringBuilder res = new StringBuilder();
        for (int i = 0; i < s.Length; i++)
            if (s[i] == c1)
                res.Append(s2);
            else
                res.Append(s[i]);
        return res.ToString();
    }
}

String Concatenation

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 */
using System;
using System.Text;
namespace Client.Chapter_6___Strings
{
  public class StringConcatenation
  {
    static void Main(string[] args)
    {
    StringBuilder MyString = new
      StringBuilder("Hello");
    MyString.Insert(0, "My");
    MyString.Append("World");
    Console.WriteLine(MyString);
    }
  }
}

Use StringBuilder to reverse a string

 
using System;
using System.Text;
class MainClass {
    public static string ReverseString(string str)
    {
       if (str == null || str.Length <= 1) 
       {
            return str;
       }
       StringBuilder revStr = new StringBuilder(str.Length);

       for (int count = str.Length - 1; count > -1; count--)
       {
           revStr.Append(str[count]);
       }
       return revStr.ToString();
   }
    public static void Main() {
        Console.WriteLine(ReverseString("The quick brown fox jumped over the lazy dog."));
    }
}

using the StringBuilder methods Replace, Insert, Append, AppendFormat, and Remove:

 
using System;
using System.Text;
class UseSBApp {
    static void Main(string[] args) {
        StringBuilder sb = new StringBuilder("Pineapple");
        sb.Replace("e", "X");
        sb.Insert(4, "Banana");
        sb.Append("Kiwi");
        sb.AppendFormat(", {0}:{1}", 123, 45.6789);
        sb.Remove(sb.Length - 3, 3);
        Console.WriteLine(sb);
    }
}