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Problem with My Class Variables Array is not working as intended - C#

To give some context. So for this project I have an array of my class variables, the cd1. That is the variable for the AudioCD and it is an array because if the user wants to enter more CD in to the array.
The problem I am getting is that when I enter more then one cd into the class array, at around the part where I add the string or artist is where I get the issue. When I go to print the class variables specific index which should be seperate, mostly everything except the artist array for the shows the last entered lines for some weird reason. I am trying to figure out why it is doing this.
PS. Sorry is my explanation is not the best.
As you see in the image. The out put should be when I input 1 for choice and 1 for the CD, the array should use the array for index 0, but it is using the array from the last inputted CD. The output should be:
man1
man2
man3
but it is:
man4
man5
man6
class AudioCD
{
// Private Variables for CDclass
public string cdTitle { get; private set; }
private string[] artists = new string[4];
public int releaseYear { get; private set; }
public string genre { get; private set; }
public float condition { get; private set; }
// Constructor for the CDclass - initializes all variables used in the CDclass
public AudioCD()
{
cdTitle = "";
artists = new string[] {"","","",""};
releaseYear = 1980;
genre = "";
condition = 0.0f;
}
// Overload Constructor for the CDclass - initializes all the variables to user input variables
public AudioCD(string cdt, string[] art, int reY, string gen, float con)
{
cdTitle = cdt;
if (artists.Length < art.Length)
{
Console.WriteLine("Your Array size is bigger then 4 for the Artist so the first 4 names will be used!");
}
artists = art;
if (reY < 1980)
{
releaseYear = 1980;
}
else
{
releaseYear = reY;
}
genre = gen;
if (con < 0.0f || con > 5.0f)
{
condition = 0.0f;
}
else
{
condition = con;
}
}
public void printAudioCD()
{
Console.Write(cdTitle + ", " + releaseYear + "\n" );
for (int i = 0; i < artists.Length; i++)
{
if (artists[i] != "" )
{
Console.WriteLine("Artist (#" + (i + 1) + "): " + artists[i]);
}
}
Console.WriteLine("Genre: " + genre);
Console.WriteLine("Condition: " + condition);
}
}
and Program class:
class Program
{
static void Main(string[] args)
{
// variables
string uI, cdtitle, genre;
int size = 0, releaseYear, choice, arrInd;
string[] artistArray = new string[4] {"", "", "", "" };
float condition;
//
AudioCD remote = new AudioCD();
Console.Write("How many CDs do you have lying around your car? ");
uI = Console.ReadLine();
size = Convert.ToInt32(uI);
AudioCD[] cd1 = new AudioCD[size];
for (int i = 0; i < size; i++)
{
Console.WriteLine("CD #" + (i + 1));
Console.Write("*Enter Title: ");
uI = Console.ReadLine();
cdtitle = uI;
Console.WriteLine("*Enter Artists (type -1 when finished):");
int j = 0;
do
{
uI = Console.ReadLine();
if (uI != "-1")
artistArray[j] = uI;
j++;
// Resize the array by One Element
if (j >= 4 && uI != "-1")
{
Array.Resize(ref artistArray, artistArray.Length + 1);
artistArray[j] = "";
}
} while (uI != "-1" );
Console.Write("*Enter Genre: ");
uI = Console.ReadLine();
genre = uI;
Console.Write("*Enter Release Year: ");
uI = Console.ReadLine();
releaseYear = Convert.ToInt32(uI);
Console.Write("*Enter Condition: ");
uI = Console.ReadLine();
condition = float.Parse(uI);
Console.Write("\n");
// switch to select which class of cd to put information in
cd1[i] = new AudioCD(cdtitle, artistArray, releaseYear, genre, condition);
}
bool isPlaying = true;
while(isPlaying)
{
Console.Write("\n");
Console.WriteLine("[Main Menu]");
Console.WriteLine("1) Album Info");
Console.WriteLine("2) Find a CD");
Console.WriteLine("3) Find an artist");
Console.WriteLine("4) Log off");
Console.Write("Choice: ");
uI = Console.ReadLine();
choice = Convert.ToInt32(uI);
switch(choice)
{
case 1:
{
Console.Write("\nWhich CD do you want? ");
uI = Console.ReadLine();
arrInd = Convert.ToInt32(uI);
if (arrInd >= 1 || arrInd <= size)
{
Console.Write(arrInd + ". ");
cd1[(arrInd - 1)].printAudioCD();
}
break;
}
case 2:
{
break;
}
case 3:
{
break;
}
case 4:
{
isPlaying = false;
break;
}
default:
{
break;
}
}
}
}
}
OUTPUT
As you see in the image. The out put should be when I input 1 for choice and 1 for the CD, the array should use the array for index 0, but it is using the array from the last inputted CD. The output should be man1,man2, and man3, but it is man4, man5, and man6.

You are using the same array in your Main() for each iteration and this is the reason why you got the artists from the last inputted CD. I mean this code snippet:
string[] artistArray = new string[4] {"", "", "", "" };
Here we can use List<T> to avoid writing code of resizing of an array and we can use Clear() method to avoid storing artists from the previous CD.
The whole code would look like this. I've refactored your code a little bit by using List:
The class AudioCD:
public class AudioCD
{
// Private Variables for CDclass
public string cdTitle { get; private set; }
private List<string> artists = new List<string>();
public int releaseYear { get; private set; }
public string genre { get; private set; }
public float condition { get; private set; }
// Constructor for the CDclass - initializes all variables used in the CDclass
public AudioCD()
{
cdTitle = "";
releaseYear = 1980;
genre = "";
condition = 0.0f;
}
// Overload Constructor for the CDclass - initializes all the variables to user input variables
public AudioCD(string cdt, List<string> art, int reY, string gen, float con)
{
cdTitle = cdt;
artists.AddRange(art);
if (reY < 1980)
{
releaseYear = 1980;
}
else
{
releaseYear = reY;
}
genre = gen;
if (con < 0.0f || con > 5.0f)
{
condition = 0.0f;
}
else
{
condition = con;
}
}
public void printAudioCD()
{
Console.Write(cdTitle + ", " + releaseYear + "\n");
for (int i = 0; i < artists.Count; i++)
{
if (artists[i] != "")
{
Console.WriteLine("Artist (#" + (i + 1) + "): " + artists[i]);
}
}
Console.WriteLine("Genre: " + genre);
Console.WriteLine("Condition: " + condition);
}
}
and Main method would look like this:
// variables
string uI, cdtitle, genre;
int size = 0, releaseYear, choice, arrInd;
List<string> artistArray = new List<string>();
float condition;
Console.Write("How many CDs do you have lying around your car? ");
uI = Console.ReadLine();
size = Convert.ToInt32(uI);
AudioCD[] cd1 = new AudioCD[size];
for (int i = 0; i < size; i++)
{
Console.WriteLine("CD #" + (i + 1));
Console.Write("*Enter Title: ");
uI = Console.ReadLine();
cdtitle = uI;
Console.WriteLine("*Enter Artists (type -1 when finished):");
int j = 0;
do
{
uI = Console.ReadLine();
if (uI != "-1")
artistArray[j] = uI;
j++;
} while (uI != "-1");
Console.Write("*Enter Genre: ");
uI = Console.ReadLine();
genre = uI;
Console.Write("*Enter Release Year: ");
uI = Console.ReadLine();
releaseYear = Convert.ToInt32(uI);
Console.Write("*Enter Condition: ");
uI = Console.ReadLine();
condition = float.Parse(uI);
Console.Write("\n");
// switch to select which class of cd to put information in
cd1[i] = new AudioCD(cdtitle, artistArray, releaseYear, genre, condition);
artistArray.Clear();
}
bool isPlaying = true;
while (isPlaying)
{
Console.Write("\n");
Console.WriteLine("[Main Menu]");
Console.WriteLine("1) Album Info");
Console.WriteLine("2) Find a CD");
Console.WriteLine("3) Find an artist");
Console.WriteLine("4) Log off");
Console.Write("Choice: ");
uI = Console.ReadLine();
choice = Convert.ToInt32(uI);
switch (choice)
{
case 1:
{
Console.Write("\nWhich CD do you want? ");
uI = Console.ReadLine();
arrInd = Convert.ToInt32(uI);
if (arrInd >= 1 || arrInd <= size)
{
Console.Write(arrInd + ". ");
cd1[(arrInd - 1)].printAudioCD();
}
break;
}
case 2:
{
break;
}
case 3:
{
break;
}
case 4:
{
isPlaying = false;
break;
}
default:
{
break;
}
}
}

How to auto-increment number and letter to generate a string sequence wise in c#

I have to make a string which consists a string like - AAA0009, and once it reaches AAA0009, it will generate AA0010 to AAA0019 and so on.... till AAA9999 and when it will reach to AAA9999, it will give AAB0000 to AAB9999 and so on till ZZZ9999.
I want to use static class and static variables so that it can auto increment by itself on every hit.
I have tried some but not even close, so help me out thanks.
Thanks for being instructive I was trying as I Said already but anyways you already want to put negatives over there without even knowing the thing:
Code:
public class GenerateTicketNumber
{
private static int num1 = 0;
public static string ToBase36()
{
const string base36 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
var sb = new StringBuilder(9);
do
{
sb.Insert(0, base36[(byte)(num1 % 36)]);
num1 /= 36;
} while (num1 != 0);
var paddedString = "#T" + sb.ToString().PadLeft(8, '0');
num1 = num1 + 1;
return paddedString;
}
}
above is the code. this will generate a sequence but not the way I want anyways will use it and thanks for help.

Though there's already an accepted answer, I would like to share this one.
P.S. I do not claim that this is the best approach, but in my previous work we made something similar using Azure Table Storage which is a no sql database (FYI) and it works.
1.) Create a table to store your running ticket number.
public class TicketNumber
{
public string Type { get; set; } // Maybe you want to have different types of ticket?
public string AlphaPrefix { get; set; }
public string NumericPrefix { get; set; }
public TicketNumber()
{
this.AlphaPrefix = "AAA";
this.NumericPrefix = "0001";
}
public void Increment()
{
int num = int.Parse(this.NumericPrefix);
if (num + 1 >= 9999)
{
num = 1;
int i = 2; // We are assuming that there are only 3 characters
bool isMax = this.AlphaPrefix == "ZZZ";
if (isMax)
{
this.AlphaPrefix = "AAA"; // reset
}
else
{
while (this.AlphaPrefix[i] == 'Z')
{
i--;
}
char iChar = this.AlphaPrefix[i];
StringBuilder sb = new StringBuilder(this.AlphaPrefix);
sb[i] = (char)(iChar + 1);
this.AlphaPrefix = sb.ToString();
}
}
else
{
num++;
}
this.NumericPrefix = num.ToString().PadLeft(4, '0');
}
public override string ToString()
{
return this.AlphaPrefix + this.NumericPrefix;
}
}
2.) Make sure you perform row-level locking and issue an error when it fails.
Here's an oracle syntax:
SELECT * FROM TICKETNUMBER WHERE TYPE = 'TYPE' FOR UPDATE NOWAIT;
This query locks the row and returns an error if the row is currently locked by another session.
We need this to make sure that even if you have millions of users generating a ticket number, it will not mess up the sequence.
Just make sure to save the new ticket number before you perform a COMMIT.
I forgot the MSSQL version of this but I recall using WITH (ROWLOCK) or something. Just google it.
3.) Working example:
static void Main()
{
TicketNumber ticketNumber = new TicketNumber();
ticketNumber.AlphaPrefix = "ZZZ";
ticketNumber.NumericPrefix = "9999";
for (int i = 0; i < 10; i++)
{
Console.WriteLine(ticketNumber);
ticketNumber.Increment();
}
Console.Read();
}
Output:

Looking at your code that you've provided, it seems that you're backing this with a number and just want to convert that to a more user-friendly text representation.
You could try something like this:
private static string ValueToId(int value)
{
var parts = new List<string>();
int numberPart = value % 10000;
parts.Add(numberPart.ToString("0000"));
value /= 10000;
for (int i = 0; i < 3 || value > 0; ++i)
{
parts.Add(((char)(65 + (value % 26))).ToString());
value /= 26;
}
return string.Join(string.Empty, parts.AsEnumerable().Reverse().ToArray());
}
It will take the first 4 characters and use them as is, and then for the remainder of the value if will convert it into characters A-Z.
So 9999 becomes AAA9999, 10000 becomes AAB0000, and 270000 becomes ABB0000.
If the number is big enough that it exceeds 3 characters, it will add more letters at the start.

Here's an example of how you could go about implementing it
void Main()
{
string template = #"AAAA00";
var templateChars = template.ToCharArray();
for (int i = 0; i < 100000; i++)
{
templateChars = IncrementCharArray(templateChars);
Console.WriteLine(string.Join("",templateChars ));
}
}
public static char Increment(char val)
{
if(val == '9') return 'A';
if(val == 'Z') return '0';
return ++val;
}
public static char[] IncrementCharArray(char[] val)
{
if (val.All(chr => chr == 'Z'))
{
var newArray = new char[val.Length + 1];
for (int i = 0; i < newArray.Length; i++)
{
newArray[i] = '0';
}
return newArray;
}
int length = val.Length;
while (length > -1)
{
char lastVal = val[--length];
val[length] = Increment(lastVal);
if ( val[length] != '0') break;
}
return val;
}

Failing to sort an Array containing objects. C#

I am working on a school project and I have spent 5 hours trying to understand how to go about sorting an Array with an object containing four dimensions. What I set out to do was to sort them by productCode or drinkName. When I read assorted threads people tell OP to use LINQ. I am not supposed to use that and, I get more and more confused as what method to use. I am told by the teacher, to use bubble sort(bad algorithm, I know) and I do that all fine on an Array containing one dimension. I resorted to try Array.Sort but then I get System.InvalidOperationException.
I am going insane and I am stuck even though I read multiple threads on the subject. I might be using ToString in the wrong manner. Any nudge would be appreciated.
class soda
{
string drinkName;
string drinkType;
int drinkPrice;
int productCode;
//Construct for the beverage
public soda(string _drinkName, string _drinkType, int _drinkPrice, int _productCode)
{
drinkName = _drinkName;
drinkType = _drinkType;
drinkPrice = _drinkPrice;
productCode = _productCode;
}
//Property for the drink name e.g. Coca Cola, Ramlösa or Pripps lättöl
public string Drink_name()
{
return drinkName;
//set { drinkName = value; }
}
//Property for the drink type e.g. Soda, fizzy water or beer
public string Drink_type()
{
return drinkType;
//set { drinkType = value; }
}
//Property for the drink price in SEK
public int Drink_price()
{
return drinkPrice;
//set { drinkPrice = value; }
}
//Property for the product code e.g. 1, 2 or ...
public int Product_code()
{
return productCode;
//set { productCode = value; }
}
//Property for the product code e.g. 1, 2 or ...
public int _Product_code
{
get { return productCode; }
set { productCode = value; }
}
public override string ToString()
{
return string.Format(drinkName + " " + drinkType + " " + drinkPrice + " " + productCode);
//return string.Format("The beverage {0} is of the type {1} and costs {2} SEK.", drinkName, drinkType, drinkPrice, productCode);
}
}
class Sodacrate
{
private soda[] bottles; //Crate the array bottles from the class soda.
private int antal_flaskor = 0; //Keeps tracks on the amount of bottles. 25 is the maximum allowed.
//Construct
public Sodacrate()
{
bottles = new soda[25];
}
public void sort_sodas()
{
string drinkName = "";
int drinkPrice = 0;
int productCode = 0;
Array.Sort(bottles, delegate (soda bottle1, soda bottle2) { return bottle1._Product_code.CompareTo(bottle2._Product_code); });
foreach (var beverage in bottles)
{
if (beverage != null)
{
drinkName = beverage.Drink_name(); drinkPrice = beverage.Drink_price(); productCode = beverage.Product_code();
Console.Write(drinkName + " " + drinkPrice + " " + productCode);
}
}
}
}
----------------------edit---------------
Thanks for the help I am getting closer to my solution and have to thursday lunch on me to solve my problems.
Still I have problem with my sort;
//Exception error When I try to have .Product_Name the compiler protests. Invalid token
public void sort_Sodas()
{
int max = bottles.Length;
//Outer loop for complete [bottles]
for (int i = 1; i < max; i++)
{
//Inner loop for row by row
int nrLeft = max - i;
for (int j = 0; j < (max - i); j++)
{
if (bottles[j].Product_code > bottles[j + 1].Product_code)
{
int temp = bottles[j].Product_code;
bottles[j] = bottles[j + 1];
bottles[j + 1].Product_code = temp;
}
}
}
}
Also my Linear search only returns one vallue when I want all those that are true to the product group. I tried a few different things in the Run() for faster experimentation. I will append the current code.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace Sodacrate
{
//Soda - contains the properties for the bottles that go in to the crate
class Soda : IComparable<Soda>
{
string drinkName;
string drinkType;
int drinkPrice;
int productCode;
//Construct for the beverage
public Soda(string _drinkName, string _drinkType, int _drinkPrice, int _productCode)
{
drinkName = _drinkName;
drinkType = _drinkType;
drinkPrice = _drinkPrice;
productCode = _productCode;
}
//Property for the drink name e.g. Coca Cola, Ramlösa or Pripps lättöl
public string Drink_name
{
get { return drinkName; }
set { drinkName = value; }
}
//Property for the drink type e.g. Soda, fizzy water or beer
public string Drink_type
{
get { return drinkType; }
set { drinkType = value; }
}
//Property for the drink price in SEK
public int Drink_price
{
get { return drinkPrice; }
set { drinkPrice = value; }
}
//Property for the product code e.g. 1, 2 or ...
public int Product_code
{
get { return productCode; }
set { productCode = value; }
}
//Override for ToString to get text instead of info about the object
public override string ToString()
{
return string.Format("{0,0} Type {1,-16} Price {2,-10} Code {3, -5} ", drinkName, drinkType, drinkPrice, productCode);
}
//Compare to solve my issues with sorting
public int CompareTo(Soda other)
{
if (ReferenceEquals(other, null))
return 1;
return drinkName.CompareTo(other.drinkName);
}
}
static class Screen
{
// Screen - Generic methods for handling in- and output ======================================= >
// Methods for screen handling in this object are:
//
// cls() Clear screen
// cup(row, col) Positions the curser to a position on the console
// inKey() Reads one pressed key (Returned value is : ConsoleKeyInfo)
// inStr() Handles String
// inInt() Handles Int
// inFloat() Handles Float(Singel)
// meny() Menu system , first invariable is Rubrik and 2 to 6 meny choises
// addSodaMenu() The options for adding bottles
// Clear Screen ------------------------------------------
static public void cls()
{
Console.Clear();
}
// Set Curser Position ----------------------------------
static public void cup(int column, int rad)
{
Console.SetCursorPosition(column, rad);
}
// Key Input --------------------------------------------
static public ConsoleKeyInfo inKey()
{
ConsoleKeyInfo in_key; in_key = Console.ReadKey(); return in_key;
}
// String Input -----------------------------------------
static public string inStr()
{
string in_string; in_string = Console.ReadLine(); return in_string;
}
// Int Input -------------------------------------------
static public int inInt()
{
int int_in; try { int_in = Int32.Parse(Console.ReadLine()); }
catch (FormatException) { Console.WriteLine("Input Error \b"); int_in = 0; }
catch (OverflowException) { Console.WriteLine("Input Owerflow\b"); int_in = 0; }
return int_in;
}
// Float Input -------------------------------------------
static public float inFloat()
{
float float_in; try { float_in = Convert.ToSingle(Console.ReadLine()); }
catch (FormatException) { Console.WriteLine("Input Error \b"); float_in = 0; }
catch (OverflowException) { Console.WriteLine("Input Owerflow\b"); float_in = 0; }
return float_in;
}
// Menu ------------------------------------------------
static public int meny(string rubrik, string m_val1, string m_val2)
{ // Meny med 2 val ---------------------
int menSvar; menyRubrik(rubrik); menyRad(m_val1); menyRad(m_val2); menSvar = menyInm();
return menSvar;
}
static public int meny(string rubrik, string m_val1, string m_val2, string m_val3)
{ // Meny med 3 val ---------------------
int menSvar; menyRubrik(rubrik); menyRad(m_val1); menyRad(m_val2); menyRad(m_val3); menSvar = menyInm();
return menSvar;
}
static public int meny(string rubrik, string m_val1, string m_val2, string m_val3, string m_val4)
{ // Meny med 4 val ---------------------
int menSvar; menyRubrik(rubrik); menyRad(m_val1); menyRad(m_val2); menyRad(m_val3); menyRad(m_val4); menSvar = menyInm();
return menSvar;
}
static public int meny(string rubrik, string m_val1, string m_val2, string m_val3, string m_val4, string m_val5)
{ // Meny med 5 val ---------------------
int menSvar; menyRubrik(rubrik); menyRad(m_val1); menyRad(m_val2); menyRad(m_val3); menyRad(m_val4); menyRad(m_val5); menSvar = menyInm();
return menSvar;
}
static public int meny(string rubrik, string m_val1, string m_val2, string m_val3, string m_val4, string m_val5, string m_val6)
{ // Meny med 6 val ---------------------
int menSvar; menyRubrik(rubrik); menyRad(m_val1); menyRad(m_val2); menyRad(m_val3); menyRad(m_val4); menyRad(m_val5); ; menyRad(m_val6); menSvar = menyInm();
return menSvar;
}
static void menyRubrik(string rubrik)
{ // Meny rubrik --------
cls(); Console.WriteLine("\n\t {0}\n----------------------------------------------------\n", rubrik);
}
static void menyRad(string menyVal)
{ // Meny rad --------
Console.WriteLine("\t {0}", menyVal);
}
static int menyInm()
{ // Meny inmating ------
int mVal; Console.Write("\n\t Menyval : "); mVal = inInt(); return mVal;
}
// Menu for adding bottles --------------------------------
static public void addSodaMenu()
{
cls();
Console.WriteLine("\tChoose a beverage please.");
Console.WriteLine("\t1. Coca Cola");
Console.WriteLine("\t2. Champis");
Console.WriteLine("\t3. Grappo");
Console.WriteLine("\t4. Pripps Blå lättöl");
Console.WriteLine("\t5. Spendrups lättöl");
Console.WriteLine("\t6. Ramlösa citron");
Console.WriteLine("\t7. Vichy Nouveu");
Console.WriteLine("\t9. Exit to main menu");
Console.WriteLine("\t--------------------\n");
}
// Screen - Slut <========================================
} // screen <----
class Sodacrate
{
// Sodacrate - Methods for handling arrays and lists of Soda-objects ======================================= >
// Methods for Soda handling in this object are:
//
// cls() Clear screen
//
//
private Soda[] bottles; //Create they array where we store the up to 25 bottles
private int antal_flaskor = 0; //Keep track of the number of bottles in the crate
//Inte Klart saknar flera träffar samt exception
public int find_Soda(string drinkname)
{
//Betyg C
//Beskrivs i läroboken på sidan 147 och framåt (kodexempel på sidan 149)
//Man ska kunna söka efter ett namn
//Man kan använda string-metoderna ToLower() eller ToUpper()
for (int i = 0; i < bottles.Length; i++)
{
if (bottles[i].Drink_name == drinkname)
return i;
}
return -1;
}
//Exception error
public void sort_Sodas()
{
int max = bottles.Length;
//Outer loop for complete [bottles]
for (int i = 1; i < max; i++)
{
//Inner loop for row by row
int nrLeft = max - i;
for (int j = 0; j < (max - i); j++)
{
if (bottles[j].Product_code > bottles[j + 1].Product_code)
{
int temp = bottles[j].Product_code;
bottles[j] = bottles[j + 1];
bottles[j + 1].Product_code = temp;
}
}
}
}
/*
//Exception error
public void sort_Sodas_name()
{
int max = bottles.Length;
//Outer loop for complete [bottles]
for (int i = 1; i < max; i++)
{
//Inner loop for row by row
int nrLeft = max - i;
for (int j = 0; j < (max - i); j++)
{
if (bottles[j].Drink_name > bottles[j + 1].Drink_name)
{
int temp = bottles[j].Drink_name;
bottles[j] = bottles[j + 1];
bottles[j + 1].Drink_name = temp;
}
}
}
}
*/
//Search for Product code
public int LinearSearch(int key)
{
for (int i = 0; i < bottles.Length; i++)
{
if (bottles[i].Product_code == key)
return i;
}
return -1;
}
//Contains the menu to choose from the crates methods
public void Run()
{
bottles[0] = new Soda("Coca Cola", "Soda", 5, 1);
bottles[1] = new Soda("Champis", "Soda", 6, 1);
bottles[2] = new Soda("Grappo", "Soda", 4, 1);
bottles[3] = new Soda("Pripps Blå", "beer", 6, 2);
bottles[4] = new Soda("Spendrups", "beer", 6, 2);
bottles[5] = new Soda("Ramlösa", "water", 4, 3);
bottles[6] = new Soda("Loka", "water", 4, 3);
bottles[7] = new Soda("Coca Cola", "Soda", 5, 1);
foreach (var beverage in bottles)
{
if (beverage != null)
Console.WriteLine(beverage);
}
Console.WriteLine("\n\tYou have {0} bottles in your crate:\n\n", bottleCount());
Console.WriteLine("\nTotal value of the crate\n");
int total = 0;
for (int i = 0; i < bottleCount(); i++)
{
total = total + (bottles[i].Drink_price);
}
/* int price = 0; //Causes exception error
foreach(var bottle in bottles)
{
price = price + bottle.Drink_price;
}
*/
Console.WriteLine("\tThe total value of the crate is {0} SEK.", total);
// Console.WriteLine("\tThe total value of the crate is {0} SEK.", price);
Screen.inKey();
Screen.cls();
int test = 0;
test = bottles[3].Product_code;
Console.WriteLine("Product code {0} is in slot {1}", test, 3);
Screen.inKey();
Console.WriteLine("Type 1, 2 or 3");
int prodcode = Screen.inInt();
Console.WriteLine(LinearSearch(prodcode));
Console.WriteLine("Product code {0} is in slot {1}", prodcode, (LinearSearch(prodcode)));
Console.WriteLine(bottles[(LinearSearch(prodcode))]);
Screen.inKey();
// sort_Sodas(); //Causes Exception error I want it to sort on either product code or product name
foreach (var beverage in bottles)
{
if (beverage != null)
Console.WriteLine(beverage);
}
}
//Print the content of the crate to the console
public void print_crate()
{
foreach (var beverage in bottles)
{
if (beverage != null)
Console.WriteLine(beverage);
//else
//Console.WriteLine("Empty slot");
}
Console.WriteLine("\n\tYou have {0} bottles in your crate:", bottleCount());
}
//Construct, sets the Sodacrate to hold 25 bottles
public Sodacrate()
{
bottles = new Soda[25];
}
// Count the ammounts of bottles in crate
public int bottleCount()
{
int cnt = antal_flaskor;
// Loop though array to get not empty element
foreach (var beverages in bottles)
{
if (beverages != null)
{
cnt++;
}
}
return cnt;
}
//Calculates the total value of the bottles in the crate
public int calc_total()
{
int temp = 0;
for (int i = 0; i < bottleCount(); i++)
{
temp = temp + (bottles[i].Drink_price);
}
return temp;
}
//Adds bottles in the crate.
public void add_Soda()
{
/*Metod för att lägga till en läskflaska
Om ni har information om både pris, läsktyp och namn
kan det vara läge att presentera en meny här där man kan
välja på förutbestämda läskflaskor. Då kan man också rätt enkelt
göra ett val för att fylla läskbacken med slumpade flaskor
*/
//I start of with adding 7 bottles to avoid having to add so many bottles testing functions. Remove block before release
bottles[0] = new Soda("Coca Cola", "Soda", 5, 1);
bottles[1] = new Soda("Champis", "Soda", 6, 1);
bottles[2] = new Soda("Grappo", "Soda", 4, 1);
bottles[3] = new Soda("Pripps Blå", "lättöl", 6, 2);
bottles[4] = new Soda("Spendrups", "lättöl", 6, 2);
bottles[5] = new Soda("Ramlösa citron", "mineralvatten", 4, 3);
bottles[6] = new Soda("Vichy Nouveu", "mineralvatten", 4, 3);
//<======================================================================================================= End block
int beverageIn = 0; //Creates the menu choice-variable
while (beverageIn != 9) //Exit this menu by typing 9 - This value should be different if we add more bottle types to add.
{
Screen.addSodaMenu(); //Calls the menu in the Screen-class
Console.WriteLine("You have {0} bottles in the crate.\n\nChoose :", bottleCount());
Screen.cup(8, 13);
int i = bottleCount(); //Keeps track of how many bottles we have in the crate. If the crate is full we get expelled out of this method
if (i == 25)
{ beverageIn = 9; }
else beverageIn = Screen.inInt(); //end
switch (beverageIn) //Loop for adding bottles to the crate exit by pressing 9
{
case 1:
i = bottleCount();
bottles[i] = new Soda("Coca Cola", "Soda", 5, 1);
i++;
break;
case 2:
i = bottleCount();
bottles[i] = new Soda("Champis", "Soda", 6, 1);
i++;
break;
case 3:
i = bottleCount();
bottles[i] = new Soda("Grappo", "Soda", 4, 1);
i++;
break;
case 4:
i = bottleCount();
bottles[i] = new Soda("Pripps Blå lättöl", "lättöl", 6, 2);
i++;
break;
case 5:
i = bottleCount();
bottles[i] = new Soda("Spendrups lättöl", "lättöl", 6, 2);
i++;
break;
case 6:
i = bottleCount();
bottles[i] = new Soda("Ramlösa citron", "mineralvatten", 4, 3);
i++;
break;
case 7:
i = bottleCount();
bottles[i] = new Soda("Vichy Nouveu", "mineralvatten", 4, 3);
i++;
break;
case 9:
i = bottleCount();
if (i == 25)
{
Console.WriteLine("\tThe crate is full\n\tGoing back to main menu. Press a key: ");
}
Console.WriteLine("Going back to main menu. Press a key: ");
break;
default: //Default will never kick in as I have error handling in Screen.inInt()
Console.WriteLine("Error, pick a number between 1 and 7 or 9 to end.");
break;
}
}
}
// Sodacrate - End <========================================
class Program
{
public static void Main(string[] args)
{
//Skapar ett objekt av klassen Sodacrate som heter Sodacrate
var Sodacrate = new Sodacrate();
Sodacrate.Run();
Console.Write("Press any key to continue . . . ");
Console.ReadKey(true);
}
}
}
}

In order to sort objects of a given kind you need to know how to compare two objects to begin with. You can sort an array of numbers because you know how to comparte 1 with 2 and 2 with -10 and so on.
Nowhere in your code are you defining how two sodas (that should be Soda by the way) compare to each other. One way to do this in c# (and .NET in general) is making your class implement a very specific interface named IComparable<T>:
public interface IComparable<T>
{
int CompareTo(T other);
}
CompareTo is what sorting algorithms like Array.Sort or Linq's OrderBy use (if not told otherwise). You need to do the same. T is a generic type, in your case you are interested in comparing sodas with sodas, so T would be Soda.
The CompareTo convention in .NET is as follows:
If this equals other return 0.
If this is less than other return -1.
If this is greater than other return 1.
null is considered to be smaller than any non null value.
Your implementation must follow this convention in order for built in sorting algorithms to work.
So first off, you need to define how you want your soda's to compare. By name? By price? All seem logical choices. If your problem specifies how sodas should compare then implement the comparison logic accordingly, otherwise choose a reasonable option.
I'll go with ordering by name, so I'd do the following:
public class Soda: IComparable<Soda>
{
....
public int CompareTo(Soda other)
{
if (ReferenceEquals(other, null))
return 1;
return drinkName.CompareTo(other.drinkName);
}
}
Because string implements IComparable<string>, implementing my own comparison logic is pretty straightforward.
Ok, now sodas know how to compare to each other and things like Array.Sort will work perfectly fine. Your own bubble sort algorithm should work well too, now that you know how to compare your softdrinks.
Another option would be to implement a IComparer<T> which is basically an object that knows how to compare two Sodas. Look into it, although in your case I think implementing IComparable<T> is a cleaner solution.
On another page, there are a few things about your code that can and should be improved:
soda should be named Soda. Classes should start with a capital letter (except maybe private nested ones).
Use properties instead of methods for Drink_name, Drink_price, Drink_type etc. and better yet, use autoimplemented properties to reduce boilerplate code.
Remove Drink form property names, the class is named Soda, so Drink is pretty much redundant not adding any useful information; its just making property names longer for no reason.
If you insist on keeping Drink use camel casing and remove _: DrinkName, DrinkType, etc.

C# NullReferenceException Thrown: My StudentList static class array is null

I have been trying to figure out what is happening with my code. I wrote an application where the user is able to enter marks of the student through a GUI application. The first form shows options, the next form is to enter the student information (name, number, mark), and the last form is to display a summary of the student information (total number of students, highest mark, lowest mark, name of student with highest mark, list of students).
To store all the student entries, I had made a student class. I created a static Student array and placed it in my ProgramFunctions class file (which is all static methods).
When I try to run the form which displays the student summary, thats where it crashes - If I look at the Auto's tab, it tells me the value of student[a] is null (I made use of a for loop to go through each student object in the array). I did trace through the adding of students and it does show that I have added new entries to the Student array.
Exceptions would be thrown at my calculation methods (highestMark, lowestMark, average). Here is my code:
class ProgramFunctions
{
private static Student[] studentList = new Student[25];
private static int counter = 0;
public static void addNewStudent(Student newStudent)
{
if (studentList.Count() == counter)
{
MessageBox.Show("The Student List is Full", "List is Full");
}
else
{
studentList[counter] = newStudent;
counter++;
}
}
public static void displayErrorMessage(String message, String title)
{
MessageBox.Show(message, title);
}
public static TextBox validateTextBox(int textboxNumber, TextBox thisTextBox)
{
if (textboxNumber.Equals(1)) //Student Name textbox
{
if (thisTextBox.Text.Length < 0 || thisTextBox.Text.Length > 100)
{
displayErrorMessage("The Student Name specified is out of allowed region (greater than 100 or less than 0 characters. Please fix this", "Student Name Error");
}
else
{
thisTextBox.Text = thisTextBox.Text.Trim();
return thisTextBox;
}
}
else if (textboxNumber.Equals(2)) //Student number text box (only 10 characters allowed)
{
if (thisTextBox.Text.Length < 0 || thisTextBox.Text.Length > 10)
{
displayErrorMessage("The student number you specified is greater than 10 characters or less than 0. Please fix this", "Student Number Error");
}
else
{
thisTextBox.Text = thisTextBox.Text.Trim();
return thisTextBox;
}
}
else
{
if (thisTextBox.Text.Length > 2 || thisTextBox.Text.Length < 0)
{
displayErrorMessage("Invalid Length for exam mark", "Invalid Exam Mark");
}
else
{
thisTextBox.Text = thisTextBox.Text.Trim();
return thisTextBox;
}
}
return null;
}
public static int getMaximumMarkPosition()
{
int highestMark = -999;
int positionFound = -1;
for (int a = 0; a < counter; a++)
{
if (studentList[a].getExamMark > highestMark)
{
highestMark = studentList[a].getExamMark; //This is where the error would occur
positionFound = a;
}
}
return positionFound;
}
public static int getHighestMark(int position)
{
return studentList[position].getExamMark;
}
public static int getLowestMark(int position)
{
return studentList[position].getExamMark;
}
public static string getHighestStudentMarkName(int position)
{
return studentList[position].getStudentName;
}
public static int getLowestMarkPosition()
{
int lowestMark = 999;
int positionFound = -1;
int studentMark = 0;
for (int a = 0; a < studentList.Count(); a++)
{
studentMark = studentList[a].getExamMark; //This is where the error would occur
if (studentMark < lowestMark)
{
lowestMark = studentMark;
positionFound = a;
}
}
return positionFound;
}
public static double calculateClassAverage()
{
double sum = 0;
double average = 0;
for (int a = 0; a < studentList.Count(); a++)
{
sum = sum + studentList[a].getExamMark;
}
average = sum / studentList.Count();
return average;
}
public static int getTotalNumberOfStudents()
{
return counter;
}
public static RichTextBox getTextBoxData(RichTextBox thisTextBox)
{
thisTextBox.Text = "STUDENT MARK DATA: \n\n";
for (int a = 1; a < studentList.Count(); a++)
{
Student currentStudent = returnStudentInformation(a);
thisTextBox.Text = thisTextBox.Text + "\n" + currentStudent.getStudentName + "\t\t" + currentStudent.getExamMark + "\t" + currentStudent.getStudentNumber;
}
return thisTextBox;
}
public static Student returnStudentInformation(int index)
{
return studentList[index];
}
}
}

It seems to me that if the student list isn't full accessing any index at counter or higher will result in a null object. I would suggest only looping up to counter:
for (int a = 1; a < counter; a++)
{
Student currentStudent = returnStudentInformation(a);
thisTextBox.Text = thisTextBox.Text + "\n" + currentStudent.getStudentName + "\t\t" + currentStudent.getExamMark + "\t" + currentStudent.getStudentNumber;
}
All this begs the question why use a static array for dynamic data when List<T> is available and is made for dynamic data.

Auto Generate alphanumeric Unique Id with C#

Total string length is 5 chars
I have a scenario, ID starts with
A0001 and ends with A9999 then
B0001 to B9999 until F0001 to f9999
after that
FA001 to FA999 then
FB001 to FB999 until ....FFFF9
Please suggest any idea on how to create this format.

public static IEnumerable<string> Numbers()
{
return Enumerable.Range(0xA0000, 0xFFFF9 - 0xA0000 + 1)
.Select(x => x.ToString("X"));
}
You could also have an id generator class:
public class IdGenerator
{
private const int Min = 0xA0000;
private const int Max = 0xFFFF9;
private int _value = Min - 1;
public string NextId()
{
if (_value < Max)
{
_value++;
}
else
{
_value = Min;
}
return _value.ToString("X");
}
}

I am a few years late. But I hope my answer will help everyone looking for a good ID Generator. None of the previous answers work as expected and do not answer this question.
My answer fits the requirements perfectly. And more!!!
Notice that setting the _fixedLength to ZERO will create dynamically sized ID's.
Setting it to anything else will create FIXED LENGTH ID's;
Notice also that calling the overload that takes a current ID will "seed" the class and consecutive calls DO NOT need to be called with another ID. Unless you had random ID's and need the next one on each.
Enjoy!
public static class IDGenerator
{
private static readonly char _minChar = 'A';
private static readonly char _maxChar = 'C';
private static readonly int _minDigit = 1;
private static readonly int _maxDigit = 5;
private static int _fixedLength = 5;//zero means variable length
private static int _currentDigit = 1;
private static string _currentBase = "A";
public static string NextID()
{
if(_currentBase[_currentBase.Length - 1] <= _maxChar)
{
if(_currentDigit <= _maxDigit)
{
var result = string.Empty;
if(_fixedLength > 0)
{
var prefixZeroCount = _fixedLength - _currentBase.Length;
if(prefixZeroCount < _currentDigit.ToString().Length)
throw new InvalidOperationException("The maximum length possible has been exeeded.");
result = result = _currentBase + _currentDigit.ToString("D" + prefixZeroCount.ToString());
}
else
{
result = _currentBase + _currentDigit.ToString();
}
_currentDigit++;
return result;
}
else
{
_currentDigit = _minDigit;
if(_currentBase[_currentBase.Length - 1] == _maxChar)
{
_currentBase = _currentBase.Remove(_currentBase.Length - 1) + _minChar;
_currentBase += _minChar.ToString();
}
else
{
var newChar = _currentBase[_currentBase.Length - 1];
newChar++;
_currentBase = _currentBase.Remove(_currentBase.Length - 1) + newChar.ToString();
}
return NextID();
}
}
else
{
_currentDigit = _minDigit;
_currentBase += _minChar.ToString();
return NextID();
}
}
public static string NextID(string currentId)
{
if(string.IsNullOrWhiteSpace(currentId))
return NextID();
var charCount = currentId.Length;
var indexFound = -1;
for(int i = 0; i < charCount; i++)
{
if(!char.IsNumber(currentId[i]))
continue;
indexFound = i;
break;
}
if(indexFound > -1)
{
_currentBase = currentId.Substring(0, indexFound);
_currentDigit = int.Parse(currentId.Substring(indexFound)) + 1;
}
return NextID();
}
}
This is a sample of the ouput using _fixedLength = 4 and _maxDigit = 5
A001
A002
A003
A004
A005
B001
B002
B003
B004
B005
C001
C002
C003
C004
C005
AA01
AA02
AA03
AA04
AA05
AB01
AB02
AB03
AB04
AB05
AC01
AC02
AC03
AC04
AC05

see this code
private void button1_Click(object sender, EventArgs e)
{
string get = label1.Text.Substring(7); //label1.text=ATHCUS-100
MessageBox.Show(get);
string ou="ATHCUS-"+(Convert.ToInt32(get)+1).ToString();
label1.Text = ou.ToString();
}

Run this query in order to get the last ID in the database
SELECT TOP 1 [ID_COLUMN] FROM [NAME_OF_TABLE] ORDER BY [ID_COLUMN] DESC
Read the result to a variable and then run the following function on the result in order to get the next ID.
public string NextID(string lastID)
{
var allLetters = new string[] {"A", "B", "C", "D", "E", "F"};
var lastLetter = lastID.Substring(0, 1);
var lastNumber = int.Parse(lastID.Substring(1));
if (Array.IndexOf(allLetters, lastLetter) < allLetters.Length - 1 &&
lastNumber == 9999)
{
//increase the letter
lastLetter = allLetters(Array.IndexOf(allLetters, lastLetter) + 1);
lastNumber = 0;
} else {
lastLetter = "!";
}
var result = lastLetter + (lastNumber + 1).ToString("0000");
//ensure we haven't exceeded the upper limit
if (result.SubString(0, 1) == "!") {
result = "Upper Bounds Exceeded!";
}
return result;
}
DISCLAIMER
This code will only generate the first set of IDs. I do not understand the process of generating the second set.

If you need to take it from the database and do this you can use something like the following.
int dbid = /* get id from db */
string id = dbid.ToString("X5");
This should give you the format you are looking for as a direct convert from the DB ID.