Convert user entered string into an object in c# - c#

I have a battleship like terminal game, the user enters a coordinate like e2, and the program checks one of the instance variables of my object Box, it checks whether hasShip is true, if its true then it will make the coordinate e2 false, and give the output "Ship destroyed"
The problem is that all my objects are called a1,a2,a3,a4,a5,b1,b2 and so on.
I have created 25 instances of the Box class. All names as such.
Once the program gets input, either e4 ,e5 etc. I want to convert that string into an object.
For example( I want to do something like this )
target = Console.ReadLine();
target.hasShip == true;
I want to convert target into an object, then use target to use the methods of the Box class.
Because the other approach requires me to make loads of if statements, which isn't clean code, doesn't look good, and is a waste if you ask me.
Thanks in advance,

New Answer: use an Array
I am slow. I did not pay attention that you are making a battleship-like game, and that we know that the "boxes" make a rectangle. We can store this efficiently in an array.
Why I did not catch up to this fact earlier? I guess I need to wake up properly.
So, use an array:
var board = new Box[5, 5];
Now, to populate it, we can do a double for loop:
for(var indexRow = 0; indexRow < 5; indexRow++)
{
for(var indexCol = 0; indexCol < 5; indexCol++)
{
board[indexRow, indexCol] = new Box();
}
}
Note: pay attention that the indexes go from 0 to 4. For a total of 5 values: {0, 1, 2, 3, 5}.
And to query from it, we will need the indexes...
Addendum on populating the array
In comments, OP has said that each Box has an id and the ship positions are picked at random.
We can give the id in the loop:
for(var indexRow = 0; indexRow < 5; indexRow++)
{
for(var indexCol = 0; indexCol < 5; indexCol++)
{
var box = new Box();
box.vhID = (((char)(((int)'a') + indexRow))).ToString() + ((char)(((int)'1') + indexCol)).ToString();
board[indexRow, indexCol] = box;
}
}
What I am doing here is constructing the id from the indexes. Basically taking the value of 'a' and adding the indexRow will give us 'a' when indexRow is 0, 'b' when it is 1 and so on. Similarly, we get the digit that represents the column.
Note: We convert the char to int, do the addition, then convert back to char... and then from char to string. Once we have string, we can concatenate them.
I do not think we need this id. But, hey, you can do it like this.
OP also mentions that he will pick 4 ship positions at random. Fair enough:
var random = new Random();
for (var ships = 0; ships < 4; ships++)
{
board[random.Next(0, 4), random.Next(0, 4)].hasShip = true;
}
Since the user inputs an string, I suggest to create a function to convert it to the index pair:
var input = Console.ReadLine();
if (TryGetCoordinates(input, out int irow, out int icol))
{
var target = board[irow, icol];
}
else
{
Console.WriteLine("The cell {0} does not exist.", input);
}
// ...
bool TryGetCoordinates(string cell, out int indexRow, out int indexCol)
{
// ...
}
Start by validating null:
bool TryGetCoordinates(string cell, out int indexRow, out int indexCol)
{
indexRow = -1;
indexCol = -1;
if (cell == null)
{
return false;
}
// ...
}
Note: Feel free to use Trim, ToUpper or ToUpperInvariant.
We know that must be a letter followed by a digit, we can validate the length:
bool TryGetCoordinates(string cell, out int indexRow, out int indexCol)
{
indexRow = -1;
indexCol = -1;
if (cell == null)
{
return false;
}
if (cell.Length != 2)
{
return false;
}
// ...
}
We extract the characters and from them the coordinates. Noting that the first one is a letter, and the other a digit. We can also validate they are withing bounds.
bool TryGetCoordinates(string cell, out int indexRow, out int indexCol)
{
indexRow = -1;
indexCol = -1;
if (cell == null)
{
return false;
}
if (cell.Length != 2)
{
return false;
}
indexRow = (int)cell[0] - (int)'a';
indexCol = (int)cell[1] - (int)'1';
return indexRow < 5 && indexRow >= 0 && indexCol < 5 && indexCol >= 0;
}
And of course, you can do a loop of the validation similar to what was explained in the old answer.
Note: the issue with value types I describe in the old answer still applies with the array.
Old Answer: Use a Dictionary
I believe you do not want to convert the string to an object (the string is an object by the way), you want to pick the Box object you previously created based on the string. And you want to do it without using if statements. What you need is a dictionary.
So, you would have Dictionary<string, Box> meaning that it is a dictionary that you can query by string and stores Box.
Addendums:
In this case, string is the key type, by which we will access the dictionary. When we add an object to the dictionary we identify it with a key, and when we retrieve it, we also use the key. The key does not have to be string, you can choose a different type. string is convenient in this case because it is what you get from Console.ReadLine().
You can create the dictionary to store whatever type you need. If you do not need Box, you can create a dictionary that stores something else.
Creating and populating the Dictionary
Then, you add to the Dictionary all your Box objects, like this:
var dict = new Dictionary<string, Box>();
// ...
dict.Add("a1", CreateBoxA1());
Where CreateBoxA1 represents whatever means you have to create the object. No, you do not need to create a method for each Box... you can do it like this:
dict.Add("a1", new Box());
Or whatever. I do not know how you create them, so consider that a placeholder, ok? ok.
Querying and retrieving values from the Dictionary
Once you have all your Box instances in your dictionary, you can get the one you need using the string:
Console.WriteLine("Enter the name of the Box:");
var name = Console.ReadLine();
var target = dict[name];
Addendum: The value you get from dict[name] is the value that you added to the dictionary with that key. So, if the user typed "a1" it dict[name] will be the value that we added with "a1" (dict.Add("a1", new Box());). Again, if what you need is not Box you can create a dictionary to store a different type.
Input validation
You can also use the Dictionary to validate if the string corresponds to a Box that exists, for example:
Console.WriteLine("Enter the name of the Box:");
var name = Console.ReadLine();
if (dict.KeyExists(name))
{
var target = dict[name];
// ...
}
else
{
Console.WriteLine("The Box {0} does not exist", name);
}
It goes without saying, but... you can make a loop based on that, for example:
Box target = null;
while(true)
{
Console.WriteLine("Enter the name of the Box:");
var name = Console.ReadLine();
if (dict.KeyExists(name))
{
target = dict[name];
break;
}
Console.WriteLine("The Box {0} does not exist", name);
}
Also, it goes without saying, but... you can add your own validations and sanitation steps. For example using ToUpper, ToUpperInvariant or Trim. And I would remind you that changing strings to lower or upper case is culture sensitive.
See also: Best Practices for Using Strings in .NET.
Editing an removing objects from the dictionary
Once you have the object you retrieved from the Dictionary...
var target = dict[name];
We can use it, and even modify it:
var target = dict[name];
if (target.hasShip) // no need for "== true" if hasShip bool
{
target.hasShip = false;
Console.WriteLine("Ship Destroyed");
}
An special note must be done if Box is value type. For a custom type that means that it is not a class but a struct. The problem with value types is that they are copied on assignment, meaning that when you do var target = dict[name]; with a value type, you get a copy. You must then update the dictionary once you manipulated it:
var target = dict[name];
if (target.hasShip) // no need for "== true" if hasShip bool
{
target.hasShip = false;
dict[name] = target;
Console.WriteLine("Ship Destroyed");
}
Note: As I said above, this is only needed for value types.
And you can even remove the Box from the dictionary if that is necesary:
dict.Remove(name);

Related

Making a simple change function for a database app C#

Sorry if this is an ultra beginner question but, I need to be able to change all field values except the item number by giving its item number not array index. I already have a add and delete feature.
using System;
struct ItemData
{
public int ItemNumber;
public string Description;
public double PricePerItem;
public int QuantityOnHand;
public double OurCostPerItem;
public double ValueOfItem;
}
class Program
{
public static void Main()
{
int invItems = 0;
var items = new ItemData[10];
while (true)
{
Console.Write("1. Add, 2. Change, 3. Delete, 4. List:");
string strx = Console.ReadLine();
var choice = int.Parse(strx);
Console.WriteLine();
switch (choice)
{
This is what I have so far but not sure where to start
case 2: //change items
{
Console.Write("Please enter an item ID No:");
string input = Console.ReadLine();
int changeItemNumber = int.Parse(input);
bool foundItem = false;
for (int x = 0; x < invItems; x++)
{
if (items[x].ItemNumber == changeItemNumber)
{
//code
}
}
if (!foundItem)
{
Console.WriteLine("Item {0} not found", changeItemNumber);
}
break;
}
It's still a little unclear what you're asking so if this is wide of the mark then feel free to let me know.
Start by mapping out the flow of the process and then implement one piece at a time. Here's a basic series of operations you'll want to do, not necessarily in this order:
Input ItemNumber.
Find index of matching record in array.
If not found report error and stop.
Get record from user.
Set ItemNumber in record to entered value.
Store record in array at same index as original.
If you think about the way the rest of the program works you should see that some of those parts - maybe most of them - are already done somewhere in your code. Your add operation probably already has the Get record from user code. Your delete operation probably has Input ItemNumber and Find index of matching record in array done already.
So pull those parts out into methods and reuse them where it makes sense. Anywhere you're writing the same code multiple times with minor changes try to see if you can extract the code into a small method you can call with maybe some parameters. Your "input a number" code for instance - used for operation selection, item number entry and presumably whatever you're doing for delete - can be pulled out to a supporting method like this one:
static int InputNumber(string prompt)
{
Console.Write($"{prompt}: ");
var inputText = Console.ReadLine();
return int.Parse(inputText);
}
Now when you want to change the way you're doing number input you have a central place to make the changes and you don't have to worry about tracking down all the places you wrote the same code.
The same goes for the rest of the pieces. When two operations share some of the same code then pull that code out to supporting methods. Finding the index of an item in the array by some criteria can - and should - be one of those:
// Return array index of matching item or -1 if not found
int ItemIndex(int itemNumber)
{
for (int i = 0; i < invItems; i++)
{
if (items[i].ItemNumber == itemNumber)
return i;
}
return -1;
}
Likewise the code - whatever that looks like - that your add operation uses to get a record from the user.
Once you do that your change item case looks a lot simpler:
case 2: // change items
var itemNumber = InputNumber("Please enter an item ID");
var index = ItemIndex(itemNumber);
if (index == -1)
{
Console.WriteLine($"Item {itemNumber} not found.");
}
else
{
var newItem = InputItemData();
newItem.ItemNumber = itemNumber;
items[index] = newItem;
}
break;
For bonus points you can actually provide the current values to the InputItemData method so the user can re-use them instead of just asking for a complete new record each time.

C# How to make use of return true/false from a method (outside of loop) called from within a while loop

I am trying to write a program that lets me enter a list of names with their respective film rating into an array (Would do a list but the course material wants me to use array). Before I add the names to the array I want to make sure that a valid rating has been entered.
I am currently using a for statement that cycles through he array length and lets the user enter each movie to the list that way. This happens in a while loop to make them re-enter the name if the rating is invalid before the name is committed to Array. I check the names by calling a method with a temporary string assigned with the current entered name and rating which will do some conditional checks and return either false or true depending on the outcome. But the way I am doing it is not working at all..
Problem is that I have no idea how to make practical use of the bool statement my method returns:
string[] filmNames = new string[ArrayLength];
for (int i = 0; i < filmNames.Length; i = i + 1)
{
bool ratingFail = true;
int displayNumber = i + 1;
while (ratingFail)
{
Console.Write($"> Enter the Name and Rating of film number {displayNumber} of {ArrayLength}: ");
string checkRating = Console.ReadLine();
CheckRating(checkRating); // currently just does "return false;" for testing purposes
if (true) // this statement is clearly not effected by whatever the return value is from above method. Why? What to do?
{
ratingFail = true;
}
else
{
filmNames[i] = checkRating; // this bit is marked as unreachable, which is is.
ratingFail = false;
}
}
}
my test method:
public static bool CheckRating(string checkRating)
{
return false;
}
I am VERY (a week) new to programming and C# so please keep in mind when answering that I may not understand particular lingo referring to programming terms outside of the scope of what you can see here within, but I will Google and research to the best of my abilities if there is no way to simplify what you want to say. Thank you for your time and effort.
if (true) // this statement is clearly not effected by whatever the return value is from above method. Why? What to do?
{
ratingFail = true;
}
This will always be true, because you're creating a variable that is always true. You want this:
ratingFail = CheckRating(checkRating)
if (!ratingFail) {
The rating is valid, do stuff here.
}
If ratingFail is true, the loop will continue.
This assumes that CheckRating returns true if the input is invalid, and false if it is valid. The variable naming here is pretty confusing, and I recommend you refactor.
I would do it this way, assuming CheckRating returns true if valid:
for (int i = 0; i < filmNames.Length; i = i + 1)
{
bool ratingValid; // Defaults to false
int displayNumber = i + 1;
while (!ratingValid)
{
Console.Write($"> Blablabla: ");
string input = Console.ReadLine();
ratingValid = CheckRating(input);
}
// Do stuff if rating is valid here. If you got here, rating is valid.
}
// edit by iluvpancakes //
I decided to add a comment made by #Sinatr since that was the (version of the) solution I personally ended up using:
if(CheckRating(checkRating))
{
[do stuff and things]
}
bool ret = CheckRating(checkRating); // currently just does "return false;" for testing purposes
if (ret)
{
[...]
}
Or, like Sinatr's comment:
if(CheckRating(checkRating))
{
[...]
}

How to iterate through multiple variables?

I'd like to create a short program to download several pictures from a website.
On a form, I would like to enter a root-link to a website with placeholders.
The placeholders can be defined with Start/End value and asc/desc.
For example: the original link is
google.de/1236-01.jpg
and I'd like to generate all links from
google.de/1236-1.jpg
up to
google.de/9955-12.jpg
So my input would be "google.de/[0]-[1].jpg" and placeholders are set to:
[0] = start 1236|end 9955|asc
[1] = start 1|end 12|asc
Via GetValidCharacters() I get a String-List of valid combinations for each entered placeholder (can be selected via ascending/descending + start&end).
The goal I'm struggling with is to build all combinations of this link, because I need to determine while runtime, how much placeholders I have.
My idea was to loop over an queue and enquueue each new build line, until there is none left with placeholders, but I don't know how to do this.
I need to make sure that all combinations are entered and they are entered only once.
private static void CreateDownloadList()
{
Queue<string> tmpQueue = new Queue<string>(); //temp queue
tmpQueue.Enqueue(DL_path); //DL_Path = google.de/[0]-[1].jpg
string line = "";
while ((line = tmpQueue.Dequeue()) != null) //not empty
{
if (line.Contains("[")) //placeholder
{
string tmpLine = line;
//how to determine, which placeholder is next?? need to know this and replace this with every combination, I get from GetValidCharacters(start, end, DESC)
}
else //done
{
_urlList.Add(line);
}
}
}
how about a simple for loop?
for (int i = 1236; i <= 9955; i++)
{
for (int j = 1; j <= 12; j++)
{
tmpQueue.Enqueue(string.Format("google.de/{0}-{1}.jpg", i, j));
}
}
I'm not going give you the full code but here is some pseudo code that would solve the problem.
given :
todostack -- stack object that holds a list of unresolved items
replace_map -- map object that holds marker string and map of all values
marker_list -- list of all markers
final_list -- list object that holds the results
(note you can probably use marker_list and replace_map in one object -- I have them separate to make my code clearer)
init :
push todostack with your starting string
set marker_list and replace_map to correct values (from parameters I assume)
clear final_list
algorithm :
while (there are any items in todostack)
{
curitem = todostack.pop
if (curitem contains a marker in marker_list)
{
loop for each replacement in replace_map
{
new_item = curitem replaced with replacement
todostack.push(new_item)
}
}
else
add curitem to final_list
}
#Hogan this was the hint to the correct way.
solution is this
private void CreateDownloadList()
{
Queue<string> tmpQueue = new Queue<string>();
tmpQueue.Enqueue(downloadPathWithPlaceHolders);
while(tmpQueue.Count > 0)
{
string currentItem = tmpQueue.Dequeue();
bool test = false;
if(currentItem.Contains("["))
{
foreach(Placeholder p in _placeholders)
{
if(currentItem.Contains(p.PlaceHolder))
{
foreach(string s in p.Replacements)
{
tmpQueue.Enqueue(currentItem.Replace(p.PlaceHolder, s));
}
test = true;
}
if(test)
break;
}
}
else
{
_downloadLinkList.Add(currentItem);
}
}
}

How to apply arraylist with variables in an Object, inside a method using a for loop in c #

A hw was given to us to change a previous hw in C# which used 2d arrays and instead of using 2d arrays we use an Array list with variables declared in an object called Students.
I would like to use a method to calculate a student best mark; however, the method is giving me an error and a warning which are the following:
Error:
CS0161 'Form1.Calc_HighestMarkOutput(int)': not all code paths return a value.
Warning:
CS0162 Unreachable code detected.
Inside the arraylist the user inputed (through use of an overload constructor):
Student Name, Maths Mark, English Mark, Maltese Mark, Email Address.
and since in the method I am returning 3 highest marks in 3 subjects attained by all students, I decided to return an array. which will be accessed by a temporary array inside the main program by selectedindex.
Please help me find the problem.
And thanks in advance.
public int[] Calc_HighestMarkOutput(int HighestMarkIndex)
{
int[] HighestMarkOutput = new int[3];
int HighestMarkMaths = 0;
int HighestMarkEnglish = 0;
int HighestMarkMaltese = 0;
int TMPHighestMarkMaths = 0;
int TMPHighestMarkEnglish = 0;
int TMPHighestMarkMaltese = 0;
for (int i = 0; i < myStudents.Count; i++) //a loop through an array list.
{
if (myStudents[HighestMarkIndex].Maths_Result > HighestMarkMaths)
{
TMPHighestMarkMaths = myStudents[HighestMarkIndex].Maths_Result;
HighestMarkMaths = TMPHighestMarkMaths;
}
if (myStudents[HighestMarkIndex].English_Result > HighestMarkEnglish)
{
TMPHighestMarkEnglish = myStudents[HighestMarkIndex].English_Result;
HighestMarkEnglish = TMPHighestMarkEnglish;
}
if (myStudents[HighestMarkIndex].Maltese_Result > HighestMarkMaltese)
{
TMPHighestMarkMaltese = myStudents[HighestMarkIndex].Maltese_Result;
HighestMarkMaltese = TMPHighestMarkMaltese;
}
HighestMarkOutput[0] = HighestMarkMaths;
HighestMarkOutput[1] = HighestMarkEnglish;
HighestMarkOutput[2] = HighestMarkMaltese;
return HighestMarkOutput;
}
You are getting an error, because the return-statement is inside the loop. If the list is empty, the return statement will never be executed. Also, you know the result only after the loop has finished. So, place the return-statement after the loop.
Since the purpose of this method is to find the highest marks, it makes no sense to pass such an index into the routine as a parameter.
Using foreach is easier than for because you don't have to deal with indexes.
Instead of returning an array, return an unnamed student containing the results. You can drop useless temporary variables.
public Student Calc_HighestMarkOutput()
{
var result = new Student(); // You also might have to add a default constructor.
foreach (Student student in myStudents) {
if (student.Maths_Result > result.Maths_Result) {
result.Maths_Result = student.Maths_Result;
}
if (student.English_Result > result.English_Result) {
result.English_Result = student.English_Result;
}
if (student.Maltese_Result > result.Maltese_Result) {
result.Maltese_Result = student.Maltese_Result;
}
}
return result;
}
You could also use Math.Max to simplify finding the maximum value
foreach (Student student in myStudents) {
result.Maths_Result = Math.Max(result.Maths_Result, student.Maths_Result);
result.English_Result = Math.Max(result.English_Result, student.English_Result);
result.Maltese_Result = Math.Max(result.Maltese_Result, student.Maltese_Result);
}
With these refactorings, the method shrinks from 22 lines (not counting empty lines and lines containing only a brace) to 7 lines.

Please explain me behaviour of C#. Object from reference

I have method with one argument which is instance of my created class - Chessfield which contain three tables - one of integers and two of bools.
In the method I have also List of Chessfield which is the return object of my method.
I am modifying chessfield (so the object from reference) and add it on list List.Add(Chessfield) several times (one time after each change).
In the end return object (so list contain several object of Chessfield) all instances are the same unrespecting my changes !
I have read similar topic and try to put 'ref' before argument and the place where I proceed this method.
Without success also I tried to create instance of Chessfield inside the method and assign to it Chessfield object from reference, then making changes on internal created object.
How I can solve it ? In the end I need to receive list of objects which each is a little bit modified from original one (from reference).
Have a nice day !!
p.s. If the code will be helpful then I cut and paste general idea code.
EDIT:
Joel undrestand me Good ! The difference is that inside object are tables and it makes the problem more complex, because I do few changes in these tables in compare to this original object. To be more clear I paste my code:
public class Chessfield
{
public int[] pieces = new int[64];
public bool[] blacks = new bool[64];
public bool[] whites = new bool[64];
public Chessfield(int[] pieces, bool[] blacks, bool[] whites)
{
this.pieces = pieces;
this.blacks = blacks;
this.whites = whites;
}
public Chessfield()
{
}
}
And method look like this:
static public List<Chessfield> MakeAllMovesForWhites(Chessfield chessfieldModel)
{
List<Chessfield> listOfPossibleMoves = new List<Chessfield>(); // list containing chessfields with changed position of figures
int indexOfCurrentPosition = 0; //start with field 0 (most top left)
foreach (bool singleEnemyChecker in chessfieldModel.whites) //iterate all fields, table of whites contain information if white field stand on the field (true, otherwise false),
{
if (singleEnemyChecker == true) //so algorithm will proceed only fields with white figure
{
int kindOfPiece = chessfieldModel.pieces[indexOfCurrentPosition]; // (table pieces contain information which kind of figure stand on particular field 0 -> empty, 1 -> soldier, 2-> tower, 3 -> horse etc...
switch (kindOfPiece)// (based on figure at field it is going to predict all possible moves
{
case 2: // tower case
if (indexOfCurrentPosition % 8 != 0) // check if the field is not most left, otherwise leave
{
int localIndexIterator = indexOfCurrentPosition; //localIndex iterate all possible moves in left direction
while (localIndexIterator % 8 != 0) // checking if tower is standing on the most left field
{
localIndexIterator = localIndexIterator - 1; //iterate all possible moves of tower for left direction
if (chessfieldModel.pieces[localIndexIterator] == 0) //if there are no figures on checking field proceed:
{
chessfieldModel.pieces[indexOfCurrentPosition] = 0; // erase tower from original position
chessfieldModel.whites[indexOfCurrentPosition] = false; // and mark that white tower is not standing there anymore
chessfieldModel.pieces[localIndexIterator] = 2; // put tower on new place
chessfieldModel.whites[localIndexIterator] = true; // and mark that on new place there is white figure
listOfPossibleMoves.Add(chessfieldModel); // here I add changed object of chessfield to list
chessfieldModel.pieces[indexOfCurrentPosition] = 2; // here I come back to original chessfield
chessfieldModel.whites[indexOfCurrentPosition] = true;
chessfieldModel.pieces[localIndexIterator] = 0;
chessfieldModel.whites[localIndexIterator] = false;
}
else //if there is figure at checking field
break; //leave this case
}
}
if (indexOfCurrentPosition % 8 != 7) // right direction case
{
// here is similar code to the sample above
}
if (indexOfCurrentPosition / 8 != 0) //top direction case
{
// here is similar code to the sample above
}
if (indexOfCurrentPosition / 8 != 7) //bottom direction case
{
// here is similar code to the sample above
}
break;
// here are another figures horse and so on...
}
}
indexOfCurrentPosition++; // go to next field...
}
return listOfPossibleMoves; //return list of changed chessfields
}
and here I call method
Logic.MakeAllMovesForWhites(currentChessfield);
I understand what is the problem. And Joel - you are explaining very good ! (y) Thank you.
My first attemp to solve it was (before I ask here):
Chessfield abc = new Chessfield();
abc = chessfieldModel;
abc.pieces[indexOfCurrentPosition] = 0;
abc.whites[indexOfCurrentPosition] = true;
abc.pieces[localIndexIterator] = 2;
abc.whites[localIndexIterator] = false;
listOfPossibleMoves.Add(abc);
Fail. I tried this in every case (create for every figure and every direction). By the way there are 33 different cases how figure can move in chess, so I had this piece of code above in this 33 places (but sometimes I put different things to tables..). But figure like tower can move left for 1,2,3,4,5,6,7 fields if there are not pieces on the left.. and this is problem that I must to create always new instance and I do not know how, because I must to create unique instance, change it a bit, and add to list.. always unique, but in different cases.
Also I have tried your solution Joel, but the problem is that I need to do some changes to original chessfield (4 rows always, but different changes for different figures).
But I tried to create a new instance, add it to list, and then change it while is already on list. Doesn't work and logic is not proper even then.
listOfPossibleMoves.Add(new Chessfield() { pieces = chessfieldModel.pieces, blacks = chessfieldModel.blacks, whites = chessfieldModel.whites });
listOfPossibleMoves[listOfPossibleMoves.Count - 1].pieces[indexOfCurrentPosition] = 0;
listOfPossibleMoves[listOfPossibleMoves.Count - 1].whites[indexOfCurrentPosition] = false;
listOfPossibleMoves[listOfPossibleMoves.Count - 1].pieces[localIndexIterator] = 2;
listOfPossibleMoves[listOfPossibleMoves.Count - 1].whites[localIndexIterator] = true;
EDIT: So maybe coming back to my first method, but how I can create unique name for objects creating in the same place ? May you recommend some technique or what I can do in this situation ?
Thanks Joel and all :)
Have a nice day (or night) everybody !
It would really help to see code in the question, but it sounds like you're doing something like this:
public class ChessField
{
public bool b1;
public bool b2;
public int i1;
}
public List<ChessField> Method(ChessField c)
{
var result = new List<ChessField>();
for (int i = 0;i<3;i++)
{
c.i1 = i;
result.Add(c);
}
return result;
}
Here's the problem: you are adding the same object to the list. result[0] refers to the same object instance as result[1] refers to the same object instance as result[2] refers to the same object instance as c. Changing a property in c changes it everywhere else in this code, because they all are variables for the same object in memory. If you need the objects to be different, you must do something to create new object instances, like this:
public List<ChessField> Method(ChessField c)
{
var result = new List<ChessField>();
for (int i = 0;i<3;i++)
{
result.Add(new ChessField() {b1 = c.b1, b2 = c.b2, i1 = i});
}
return result;
}
or my preferred style would do this:
public IEnumerable<ChessField> Method(ChessField c)
{
return Enumerable.Range(0, 3)
.Select(i => new ChessField() {b1 = c.b1, b2 = c.b2, i1 = i});
}

Categories

Resources