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C# Sliding Window Algorithm

So i have to sent a message from a Sender to a Destination(Shown in main class) by specifing how many letters i wanna sent (the size variable).When the laters left are less than letters i wanna sent,it automaticaly sent how many i have left,and after the algorithm stops;
The problem is when the message i supossely sent is 9 characters long,and when i wanna sent 6 characters and another 3 it throws me an error (System.IndexOutOfRangeException: 'Index was outside the bounds of the array.'
)
using System;
using System.Text;
using System.Threading;
namespace homework
{
internal class slidingWindow
{
private string name;
private StringBuilder message = new StringBuilder();
private bool isSource = false;
private int fin = 0;
public slidingWindow(string name, bool isSource)
{
this.name = name;
this.isSource = isSource;
}
public void messageSet(string _message)
{
if (isSource == true) message.Append(_message);
else Console.WriteLine("Is not source");
}
public void sendMessage(slidingWindow destination)
{
int counter= 0;
Console.WriteLine("Specify the size of data sent: ");
int size = Convert.ToInt32(Console.ReadLine()); //the size of how manny letters i should send
int countCharacterSent=size;
for (int x = 0; x < message.Length+(message.Length%size); x = x + size)
{
counter++;
for (int y = 0; y < size; y++)
{
if (x + size > message.Length + (message.Length % size)) { size=size-(message.Length%size); countCharacterSent = message.Length; }
else {destination.message.Append(message[x + y]); }
}
Console.WriteLine("Sennder---- " + destination.message + " ----->Destination" + " (" + counter+ ")"+ " Characters sent: "+size+ " Characters received: "+countCharacterSent+ '\n');
Thread.Sleep(TimeSpan.FromSeconds(1));
countCharacterSent = countCharacterSent + size;
}
fin = 1;
if (message.Length % size != 0) destination.fin = 1;
destination.print();
}
public void print()
{
Console.WriteLine("Destination has receveid the message: " + message+" FIN: "+fin);
}
}
and the main class
using System;
namespace homework
{
class main
{
static void Main(string[] args)
{
while (true)
{
int option = 0;
slidingWindow a = new slidingWindow("Sender", true);
a.messageSet("exampless");
slidingWindow b = new slidingWindow("Destination", false);
a.sendMessage(b);
Console.WriteLine("If you want to exit write 1:"+'\n');
option = Convert.ToInt32(Console.ReadLine());
if (option == 1) break;
}
}
}
example:
input:
message='example'
size=3;
output:
exa
mpl
e

Honestly I can see you try hard (too hard) to handle the limit case of the last block that can just not meet the expect size.
Since you do this in dotnet C#, and depending on the version you will see you have many different options....
Especially to create a batch of x out of a simple sequence....
here is a homemade version of things you will find for free in libraries like moreLinq and probably in latest Linq lib..
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Linq;
public static class LinqExtensions
{
public static IEnumerable<IEnumerable<T>> Batch<T>(this IEnumerable<T> source, int size)
{
return source
.Select( (c, i) => (c, index : i))
.Aggregate(
new List<List<T>>(),
(res, c) =>
{
if (c.index % size == 0)
res.Add(new List<T> { c.c });
else
res.Last().Add(c.c);
return res;
});
}
}
public class Program
{
public static void Main(string[] args)
{
var test = "xxxxxxxxxxx".AsEnumerable();
var blocks = test
.Batch(3)
.Select(b=> new string(b.ToArray()));
blocks.ToList().ForEach(System.Console.WriteLine);
}
}

NullReferenceException? Why? [closed]

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Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
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I try to calculate the total collective age of my passengers in calc_total_age() this works before I add a passenger and writes out "0". However when I add a passenger I get NullReferenceException, I have tried different things but I just can't wrap my head around what I'm doing. I need a little shove in the right direction and maybe and explanation of what the he** I am doing and I don't know what my GetAge() does either really I have tried to call it but it doesn't seem to work.
This is all my code:
using System;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.Threading.Tasks;
class Program {
public static void Main (string[] args) {
//Console.Clear();
Console.WriteLine("Hi, welcome to the Buss-Simulator!");
Console.ReadKey();
var mybus = new Bus();
mybus.Run();
Console.ReadKey();
}
}
using System;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.Threading.Tasks;
class Bus {
public int total_passengers = 0;
public Passenger[] info_passengers;
public int totalAge = 0;
public int totalSeats = 25;
public void Run()
{
info_passengers = new Passenger[25];
string [] menu = new string[]{"1. Pick up passenger.", "2. Show who's on the bus.", "3. Calculate total age of passengers"};
int MenuSelect = 0;
while (true)
{
Console.Clear();
Console.WriteLine("What do you want to do?");
Console.WriteLine();
Console.CursorVisible = false;
if (MenuSelect == 0)
{
Console.WriteLine(menu[0] + " ⭅");
Console.WriteLine(menu[1]);
Console.WriteLine(menu[2]);
}
else if(MenuSelect == 1)
{
Console.WriteLine(menu[0]);
Console.WriteLine(menu[1] + " ⭅");
Console.WriteLine(menu[2]);
}
else if(MenuSelect == 2)
{
Console.WriteLine(menu[0]);
Console.WriteLine(menu[1]);
Console.WriteLine(menu[2] + " ⭅");
}
var keyPressed = Console.ReadKey();
if(keyPressed.Key == ConsoleKey.DownArrow && MenuSelect != menu.Length -1)
{
MenuSelect++;
}
else if (keyPressed.Key == ConsoleKey.UpArrow && MenuSelect >= 1)
{
MenuSelect--;
}
else if (keyPressed.Key == ConsoleKey.Enter)
{
switch (MenuSelect)
{
case 0:
add_passengers();
break;
case 1:
print_passengers();
break;
case 2:
calc_total_age();
break;
}
}
}
}
public void add_passengers()
{
if (total_passengers == 25)
{
Console.WriteLine("\nBus is full!");
System.Threading.Thread.Sleep(2000);
return;
}
try
{
Console.WriteLine("\nType the name, age & gender of your passenger.");
Console.Write("\nName: ");
string name = Console.ReadLine();
Console.Write("\nAge: ");
int age = Convert.ToInt32(Console.ReadLine());
Console.Write("\nGender: ");
string gender = Console.ReadLine();
Passenger passenger = new Passenger(aName: name, aAge: age, aGender: gender);
Array.Resize(ref info_passengers, info_passengers.Length + 1);
info_passengers[info_passengers.Length - 1] = passenger;
}
catch (Exception e)
{
Console.WriteLine("\nFollow instructions.");
System.Threading.Thread.Sleep(2000);
return;
}
total_passengers++;
Console.WriteLine("You boarded 1 Passenger." + "\nThere are " + (totalSeats - total_passengers) + " seats left.");
System.Threading.Thread.Sleep(2000);
return;
}
public void print_passengers()
{
Console.WriteLine();
foreach (var i in info_passengers)
{
Console.WriteLine(i);
}
Console.ReadKey();
}
public void calc_total_age()
{
for (int i = 0; i < total_passengers; i++)
{
totalAge += info_passengers[i].age;
}
Console.WriteLine(totalAge);
Console.ReadKey();
}
}
using System;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.Threading.Tasks;
class Passenger{
public string name;
public int age;
public string gender;
public Passenger(string aName, int aAge, string aGender)
{
name = aName;
age = aAge;
gender = aGender;
}
public override string ToString()
{
return string.Format($"This is {name}, {gender}, {age} years old.");
}
public int GetAge()
{
return age;
}
}

you don't need to resize info_passengers array since it is enough for total passangers. When you add an extra array cell, you add a passanger to the end of arry, but you still have the empty cells in the beginnig of array with null that are causing the exception.
so remove this code
Array.Resize(ref info_passengers, info_passengers.Length + 1);
and fix this
total_passengers++;
info_passengers[ total_passengers-1] = passenger;
and don't forget to remove total_passengers++; from here
Console.WriteLine("You boarded 1 Passenger." + "\nThere are " + (totalSeats - total_passengers) + " seats left.");
and add totalAge=0 in calc_total_age
public void calc_total_age()
{
totalAge=0;
for (int i = 0; i < total_passengers; i++)
{
totalAge += info_passengers[i].age;
}
and it is not a very good idea to hide errors in your catch blok. I would make it
catch (Exception e)
{
Console.WriteLine("\n Error!!! " + e.Message);
System.Threading.Thread.Sleep(2000);
return;
}

The answer to this one is very simple!
You declare:
public Passenger[] info_passengers;
This actually creates a pointer to a Passenger array, which (like all pointers) is initially null. It does not create the actual array itself.
When your code comes to call:
Array.Resize(ref info_passengers, info_passengers.Length + 1);
the method Resize expects the array parameter to point to an array. However, info_passengers is still null. So you get the exception.
I think all you need to do is to initialise info_passengers to an new empty array, like this:
public Passenger[] info_passengers = new Passenger[]();
and then I think it'll all work.

How do I set a value in one method and then return that value to another method?

I need some help. If I understand this right, the value of "int F" gets sent to "FtoC" converted and then returned to the MenuSelect1 method.
Now I want to return or save the value "int C" has after its been converted to the MenuSelect2 method? I have tried everything I can think of, but I just get errors. (I have reset the code to original state now where MenuSelect1 and 2 är void). Whats an easy way to solve this? Thank you.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
public static class SecondClass {
public static int FtoC(int fahrenheit)
{
int C = ((fahrenheit - 32) * 5) / 9;
return C;
}
public static void MenuSelect1()
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
int C = SecondClass.FtoC(F);
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
break;
}
}
Console.ReadKey();
}
public static void MenuSelect2()
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write("Temperature: {0}");
Console.ReadKey();
}
}

You could also save the value of C as a property / field in your class. Here is an example of saving it as a field called _celcius:
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
public static class SecondClass {
private static int _celcius = 0; // <--- Your field
public static int FtoC(int fahrenheit)
{
int C = ((fahrenheit - 32) * 5) / 9;
return C;
}
public static void MenuSelect1()
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
_celcius = SecondClass.FtoC(F); // <--- Assign field here
if (_celcius < 80 || _celcius > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(_celcius + "°C is perfect. Start the sauna and enjoy!");
break;
}
}
Console.ReadKey();
}
public static void MenuSelect2()
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write("Temperature: {0}", _celcius); // <--- Use your field here
Console.ReadKey();
}
}```

You either call the MenuSelect2() directly from the MenuSelect1()
public static void MenuSelect1()
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
int C = SecondClass.FtoC(F);
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
// here
MenuSelect2(C);
break;
}
}
Console.ReadKey();
}
public static void MenuSelect2(int C)
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write($"Temperature: {C}"); // <- notice the $ for interpolated strings.
}
Or return the value from the MainSelect1() to the caller which calls the MainSelect2() method.
public static void Main()
{
// get the temperature
int C = MenuSelect1();
// pass it to the other method.
MenuSelect2(C);
Console.ReadKey();
}
public static int MenuSelect1() // <- change the signature (return int)
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
int C = SecondClass.FtoC(F);
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
return C; // return the value to the caller.
}
}
}
public static void MenuSelect2(int C)
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write($"Temperature: {C}"); // <- notice the $ for interpolated strings.
}
I rather use the second suggestion, because this way the MenuSelect1() isn't tightcoupled to MenuSelect2() and can be reused for other purposes.

The problem at this point is that the variable C is instantiated and stored inside the method MenuSelect1(), what you should do is create a class variable like int fahrenheitValue and then inside the menuSelect1 method use this.fahrenheitValue = C so the value is stored inside the class variable and then you can access it from everywhere

All the variables that are defined in MenuSelect1() will NOT be visible as soon as the method ends.
You can define a static property in your "SecondClass"
private static int degreesCelsius;
Then you can set this property in
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
degreesCelsius = C;
break;
}
In your MenuSelect2() method you can use it.
Console.Write("Temperature: {0}", degreesCelsius);

How to determine input when the can have a variable?

I'm working on this commandline based dice. And I want it to be able to output statistics and reset those internal statistics. Currently I have the following classes: Dice and DiceInterface.
I want the user to be able to use the following format for input: "'Throw' to throw the dice, alternate use 'Throw(x)', 'Stat(side)' to see how many times (side) has been thrown, or 'Reset' to reset thrown statistics"
I need a way to determine if the user has typed Throw, Throw(x), Stat(side) or Reset. Throw and Reset are obvious to me but I find it quite difficult to imagine a way to do Throw(x) and Stat(side). Does anyone have any tips or a solution?
Thanks in advance!
using System;
using System.Collections.Generic;
using System.Text;
namespace Oefening_2
{
class DiceInterface
{
static void Main()
{
StartProgram();
}
static void StartProgram()
{
Console.WriteLine("Hello, how many sides would you like the dice to have?");
var input = Console.ReadLine();
if (Int32.TryParse(input, out int number))
{
int desiredSides = number;
Dice NewDice = new Dice(desiredSides);
Console.WriteLine("What would you like to do? ");
Console.WriteLine("Type: 'Throw' to throw the dice, alternate use 'Throw(x)', 'Stat(side)' to see how many times (side) has been thrown, or 'Reset' to reset thrown statistics");
MainIO(NewDice);
}
else
{
Console.WriteLine("That is not an integer! The program will restart now...");
StartProgram();
}
}
static void MainIO(Dice CurrentDice)
{
Console.Write("Input: ");
string input = Console.ReadLine();
//Throw
if (input == "Throw")
{
Console.WriteLine(CurrentDice.Throw());
MainIO(CurrentDice);
}
//Throw(x)
else if(input == "")
//Thrown(side)
//Reset
else if (input == "Reset")
{
CurrentDice.ResetStatistics();
MainIO(CurrentDice);
}
}
}
}
using System;
namespace Oefening_2
{
class Dice
{
public int Sides { get; set; }
private readonly Random _rnd = new Random();
public int[] Thrown;
public Dice(int sides)
{
Sides = sides;
Thrown = new int[sides--];
}
public Dice():this(6)
{
}
public int Throw()
{
int thrownNumber = _rnd.Next(1, Sides);
Thrown[thrownNumber]++;
return thrownNumber;
}
public int NrOfTimesThrown(int side)
{
int result;
result = Thrown[side];
return result;
}
public void ResetStatistics()
{
for(int i = 0 ; i < Sides; i++)
{
Thrown[i] = 0;
}
}
}
}

This can be fairly simply done with StartsWith to check if a string starts with some prefix, and use .Remove to get anything after this prefix:
if(input.StartsWith("Stat"){
var parameterString = input.Remove(0, "Stat".Length);
if(int.TryParse(parameterString , out var side){
...
}
}

If I correctly understood your problem, it could be solved with an approach like this:
Console.WriteLine("Enter a value");
var s = Console.ReadLine();
if(s.Contains('('))
{
int pFrom = s.IndexOf("(");
int pTo = s.LastIndexOf(")");
var myChoice = s.Substring(0, pFrom);
var myValue = s.Substring(pFrom + 1, pTo - pFrom);
Console.WriteLine($"You choosed : {myChoice}");
Console.WriteLine($"With a value of: {myValue}");
}
This is just a brief example of how to "understand" if there is a value and then recover it.
I hope this could help you somehow.

Line placement error in c#

I could not find anything but the program includes five serious errors and some line placement faults. What are the faults? Thank you for your help
using System;
class Program
{
static void Main(string[] args)
{
int deger1, deger2;
deger2 = Convert.ToInt32(Console.ReadLine());
for (kivir =0; kivir <2; kivir++)
{
if (deger1 == 56)
Console.WriteLine(Ekle(kivir, deger1));
deger2--;
else deger1 = 56;
}
}
static int Ekle(int deger1, int deger2)
{
return deger1 + deger2;
}
}

kivir is not declared as a variable.
your if statement appears to have multiple statements but is missing blocks ({...}).
deger1 is not initialized
This version can compile:
using System;
class Program
{
static void Main(string[] args)
{
int deger1 = 0, deger2;
deger2 = Convert.ToInt32(Console.ReadLine());
for (int kivir =0; kivir <2; kivir++)
{
if (deger1 == 56)
{
Console.WriteLine(Ekle(kivir, deger1));
deger2--;
}
else
{
deger1 = 56;
}
}
}
static int Ekle(int deger1, int deger2)
{
return deger1 + deger2;
}
}
However, it will close the console window before you can see the output. You need to add one more Console.ReadLine() before the end of the main method.

I found one error to,there isn't a namespace.