Hi I am trying to make a mastermind game where I having the user guess a number sequence between 4-10 instead of colours but for some reason my GetRandomNumberCount and my GenerateRandomNumber give me the error not all code paths return a value.
Any guidance would be appreciated
public static int GetRandomNumberCount()
{
//Create the secret code
Random RandomClass = new Random();
int first = RandomClass.Next(1, 5);
int second = RandomClass.Next(1,5);
int third = RandomClass.Next(1,5);
int forth = RandomClass.Next(1,5);
Console.WriteLine ("You are playing with M#sterB#t");
Console.WriteLine ("Bot Says : You Go First");
Console.WriteLine("Game Settings ");
Console.WriteLine("The Game Begins");
}
That's because they don't return a value. For example GetRandomNumberCount has Intset as its return type, but has no return statement. If you want to return nothing set the return type to void. Using that as an example
public static int[] GetRandomNumberCount()
{
//Create the secret code
Random RandomClass = new Random();
int first = RandomClass.Next(1, 5);
int second = RandomClass.Next(1,5);
int third = RandomClass.Next(1,5);
int forth = RandomClass.Next(1,5);
Console.WriteLine ("You are playing with M#sterB#t");
Console.WriteLine ("Bot Says : You Go First");
Console.WriteLine("Game Settings ");
Console.WriteLine("The Game Begins");
//This is where you would return a value, but in this case it seems you want to return an array of ints
//Notice how I changed the return type of the method to Int[]
int[] numbers = new int[4];
numbers.Add(first);
numbers.Add(second);
numbers.Add(third);
numbers.Add(fourth);
//This is the actual return statement that your methods are missing
return numbers;
}
regardless of whether you actually want to return an int array is moot though, Im only guessing. The real take away is that the int[] in
public static int[] GetRandomNumberCount()
declares a return type meaning you need a a return statement.
You are getting that error cause your method signature says it returns a int but your are not returning anything. What I see is, you meant to have a method with void return type like below since you are just printing the lines
public static void GetRandomNumberCount()
{
//Create the secret code
Random RandomClass = new Random();
int first = RandomClass.Next(1, 5);
int second = RandomClass.Next(1,5);
int third = RandomClass.Next(1,5);
int forth = RandomClass.Next(1,5);
Console.WriteLine ("You are playing with M#sterB#t");
Console.WriteLine ("Bot Says : You Go First");
Console.WriteLine("Game Settings ");
Console.WriteLine("The Game Begins");
}
Related
I'm following along in a book and trying the 'challenges'. Here I'm running into a problem with properly returning and passing an array between methods. Something goes wrong with returning the array, especially from the second method, and then passing it to third to print.
I understand the stack, heap, values and references on the conceptual level, but something clearly goes
wrong.
Each method appears to work otherwise.
using System;
namespace PracticeArray
{
class Program
{
static int[] GenerateNumbers()
{
Console.WriteLine("Enter a number to generate array from:");
string input = Console.ReadLine();
int inputNumber = Convert.ToInt32(input);
int[] generatedArray = new int[inputNumber];
for (int i = 0; i < generatedArray.Length; i++)
{
generatedArray[i] = i;
}
return generatedArray;
}
static int[] Reverse(int[] arrayToReverse)
{
int count = arrayToReverse.Length;
int[] arrayToReturn = new int[count];
count--;
for (int i = 0; i < arrayToReturn.Length; i++)
{
arrayToReturn[i] = arrayToReverse[count--];
}
return arrayToReturn;
}
static void PrintNumbers(int[] numbersToPrint)
{
foreach (int singleNumber in numbersToPrint)
{
Console.Write(singleNumber + ", ");
}
}
static void Main(string[] args)
{
int[] numbers = GenerateNumbers();
Reverse(numbers);
PrintNumbers(numbers);
}
}
}
The problem
The array you return is a new array:
Take a look in your Reverse function. You create a new array called arrayToReturn and return that array. You also never modify the original input array arrayToReverse.
static int[] Reverse(int[] arrayToReverse) // this input array is never modified
{
int count = arrayToReverse.Length;
// ...
arrayToReturn = new int[count]; // Here is the new array
// ...
return arrayToReturn; // you return the new array
}
Now look at where you called Reverse you passed in some generated numbers, but you ignore the return value of the function so you never find out what the new array is. Remember we already established above that you don't modify the elements of the input array. So numbers will remain unchanged.
static void Main(string[] args)
{
int[] numbers = GenerateNumbers();
Reverse(numbers); // you ignored the return value of `Reverse`
PrintNumbers(numbers); // These are the original unreversed numbers
}
To Fix
Option #1 - New variable to store the result
To fix this, store the array returned from Reverse in a variable and print those numbers.
static void Main(string[] args)
{
int[] numbers = GenerateNumbers();
int[] reversedNumbers = Reverse(numbers);
PrintNumbers(reversedNumbers);
}
Option #2 - Reuse the same variable to store the result
In this option you simply discard the original array by taking the new reversed numbers array returned from Reverse and assigning it to the numbers variable. After that assignment, numbers will refer to the reversed array that was returned from Reverse. The original array is orphaned and forgotten - eventually garbage collected.
static void Main(string[] args)
{
int[] numbers = GenerateNumbers();
// repurpose the `numbers` variable to store the result.
numbers = Reverse(numbers);
PrintNumbers(numbers);
}
I'm trying to do a dice game but for some reason this error occurs.
Unable to cast object of type 'Dice' to type 'System.IConvertible'
Here is my code:
class Dice
{
int result;
public void DiceRoll()
{
Random rnd = new Random();
result = rnd.Next(1, 7);
}
}
Console.WriteLine("Player 1 Turn" + roll);
int enterscore1 = Convert.ToInt32(roll);
Console.WriteLine("Player 2 Turn" + roll);
int enterscore2 = Convert.ToInt32(roll);
Some notes:
You'd often use one of Convert.ToInt32, int.TryParse, or int.TryParse when getting input from a user (i.e. as text) and want to get its numeric value (as an int value).
Here you have the bones of a Dice class which works with an int already, so there is no need for conversion.
I would strongly recommend you don't try to implement IConvertible like the message implies - that's not really what it's designed for.
Note that for cases like yours, it's strongly recommended you have a single instance of a Random because the constructor is
using a time-dependent default seed value.
so making multiple Random instances in quick succession are liable to use the same seed. If you do this, because methods on the Random class are not threadsafe, you should lock on some object to prevent multiple threads from calling its methods at the same time (as I do below).
There are several ways to do what you want. Here are a few:
Have a single instance of a Dice and roll it many times:
public class Dice
{
private static readonly Random random = new Random();
public int Result
{
get;
private set;
}
public void Roll()
{
lock ( random )
Result = random.Next(1, 7);
}
}
public static void Main()
{
var dice = new Dice();
dice.Roll();
var player1Result = dice.Result;
Console.WriteLine("Player 1 rolls: " + player1Result);
dice.Roll();
var player2Result = dice.Result;
Console.WriteLine("Player 2 rolls: " + player2Result);
}
(try it here)
Notice that I've assigned a variable for each roll - this enables you to compare the results using > and < to find out who wins.
Have a separate Dice instance for each player:
public class Dice
{
private static readonly Random random = new Random();
private readonly int _minValue;
private readonly int _maxValue;
public Dice(int minValue, int maxValue)
{
_minValue = minValue;
_maxValue = maxValue;
}
public int Result
{
get;
private set;
}
public void Roll()
{
lock ( random )
Result = random.Next(_minValue, _maxValue + 1);
}
}
public static void Main()
{
var player1Dice = new Dice(1, 6);
player1Dice.Roll();
var player1Result = player1Dice.Result;
Console.WriteLine("Player 1 rolls: " + player1Result);
var player2Dice = new Dice(1, 5);
player2Dice.Roll();
var player2Result = player2Dice.Result;
Console.WriteLine("Player 2 rolls: " + player2Result);
}
(try it here)
You can still do comparisons, but because you have different Dice instances, you could add your own constructor to Dice to, for instance, stack the odds in favour of one player (here I've made the second player's dice only ever roll 1-5).
Just have a static Dice class
public static class Dice
{
private static readonly Random random = new Random();
public static int Roll()
{
lock ( random )
return random.Next(1, 7);
}
}
public static void Main()
{
var player1Result = Dice.Roll();
Console.WriteLine("Player 1 rolls: " + player1Result);
var player2Result = Dice.Roll();
Console.WriteLine("Player 2 rolls: " + player2Result);
}
(try it here)
If you're never going to do anything fancy with the Dice and it isn't expected to have any state (e.g. roll different values, or know about previous rolls) and you need to have a separate class, this is how I'd do it. You don't need a constructor because Dice is static. Again, you can do comparisons with the two results.
If you declared roll as a variable of Dice class, your code should be
int enterscore1 = Convert.ToInt32(roll.result);
Console.WriteLine("Player 2 Turn" + roll);
int enterscore2 = Convert.ToInt32(roll.result);
Unable to cast object of type 'Dice' to type 'System.IConvertible'
This error means you are putting argument that has no IConvertible interface which is essential to Convert class methods.
you need to include int enterscore1 = DiceRoll(); and it would help to define the random variable as an integer within the dice roll method
I'm trying to get a user to input 1 value into the array, and then exit to main menu, then the next person to enter a value gets his put into the next bracket, not replace slot 0, currently it just loops the first array bracket and replaces the number. Help would be much appreciated
static void Main(string[] args)
{
int[] myArray = new int[10];
while (true)
{
int enteredNumber;
Startmenu();
enteredNumber = Convert.ToInt32(Console.ReadLine());
if (enteredNumber == 1)
{
for (int i = 0; i < myArray.Length; i++)
{
Console.WriteLine("Insert Number:");
myArray[i] = Convert.ToInt32(Console.ReadLine());
}
Console.Clear();
Console.WriteLine("blabla");
Thread.Sleep(2000);
Console.Clear();
}
if (enteredNumber == 9)
{
if (Login(1234, 3) == true)
{
foreach (int number in myArray)
{
Console.WriteLine(number);
}
}
}
}
}
One problem I think you have in that code is that you're trying to do too much in one method. You might want to break out discreet operations into separate methods, which will both enable code reuse and also serve to make your code more readable.
First, you need a method that will get an int from the user. Let's write a helper method that does that, which takes in a string that will be displayed as a prompt to the user, and which will continue to prompt them until they enter a valid int. We can use int.TryParse to determine if they enter a valie int. It takes a string argument to parse, and an out int that will contain the parsed value if it succeeds. The method itself returns true if it was successful:
private static int GetIntFromUser(string prompt)
{
int result;
do
{
Console.Write(prompt);
} while (!int.TryParse(Console.ReadLine(), out result));
return result;
}
You don't show the code for ShowMenu, but it probably gives the user some menu choices, and I've added the functionality where it returns the menu choice entered by the user:
private static int ShowMenu()
{
int menuChoice;
do
{
Console.Clear();
Console.WriteLine("Main Menu:");
Console.WriteLine("1. Input an array item");
Console.WriteLine("9. Print the numbers\n");
menuChoice = GetIntFromUser("Enter your choice (1 or 9): ");
} while (menuChoice != 1 && menuChoice != 9);
return menuChoice;
}
Now, another thing you seem to be missing that might help here, is to add a "pause" to the program after printing out the array items, so the user has a chance to see them. I think this is probably the main problem. Currently you write them all out to the screen, then the while loop runs again and you don't get a chance to see it. Here's a helper method that asks the user to press a key when they're ready, and then waits for the user to press a key:
private static void WaitForUserInput()
{
Console.Write("\nPress any key to continue...");
Console.ReadKey();
}
We can also put the code to populate the array in a separate method. Since you want to enable the user to populate only one item at a time, we will need to keep track of which item is the next one to populate, so we'll set a class-level variable for that, and make use of it in the method. We'll populate that item, then increment the variable. Of course we have to first make sure the next item is not greater than the number of items available:
private static int NextIndexToPopulate = 0;
private static void PopulateNextArrayItem(int[] array)
{
if (array == null) return;
if (NextIndexToPopulate >= array.Length)
{
Console.WriteLine("The array is full; no items left to enter.");
WaitForUserInput();
}
else
{
array[NextIndexToPopulate] = GetIntFromUser("Enter number to insert: ");
NextIndexToPopulate++;
}
}
And another method can be used to print out the array:
private static void PrintArray(int[] array)
{
if (array == null)
{
Console.WriteLine("The array is null - nothing to print.");
}
else
{
Console.WriteLine("Here are the array items entered:");
for (int i = 0; i < NextIndexToPopulate; i++)
{
Console.WriteLine(array[i]);
}
}
}
You also didn't show the Login code, so here's a dummy method I'll use that always returns true:
private static bool Login(int first, int second)
{
return true;
}
Now, with all that extra stuff encapsulated in methods, our main code becomes a little more readable, there's less chance for errors, and when there are errors, it's more clear what they are:
private static void Main()
{
int[] myArray = new int[10];
while (true)
{
int enteredNumber = ShowMenu();
if (enteredNumber == 1)
{
PopulateNextArrayItem(myArray);
}
else if (enteredNumber == 9)
{
if (Login(1234, 3))
{
PrintArray(myArray);
WaitForUserInput();
}
}
}
}
So I am doing a Homework assignment for c#. The assignment requires the use of 2 arrays, one to hold names and the other to hold scores. We are then to calculate the average score, display the below average scores, and display the scores according to name. I am having a significant amount of difficulty passing the arrays by reference/value in order to use the data in them and maintain my code using separate modules. The arrays have to hold up to 100 individual pieces of data.
class Program
{
static void Main(string[] args)
{
string[] playerNames = new string[100];
int[] playerScores = new int [100];
int numPlayers = 0;
double averageScore;
DisplayData(playerNames);
}
static void InputData(string[] playerNames, int[] playerScores, ref int numPlayers)
{
string playerName;
do
{
int i = 0;
Console.WriteLine("Enter the name of the player...Enter \"Q to exit...");
playerName = Console.ReadLine();
if (playerName == "Q" || playerName == "q")
Console.WriteLine("No further user input needed...\n");
else
playerNames[i] = playerName;
Console.WriteLine("Enter the score of the player...");
int playerScore = Convert.ToInt32(Console.ReadLine());
playerScores[i] = playerScore;
numPlayers += i;
i++;
}
while (playerName != "Q");
}
static void CalculateAverageScore(int[] playerScores, ref int averageScore)
{
InputData(playerScores);
InputData(ref numPlayers);
int averageScores = 0;
averageScores = playerScores / numPlayers;
}
The biggest question I have is that I cannot seem to pass the array data. I am plagued by "No overload method for "Input Data" or whatever method I am using. So I'm curious as to how I can pass the array data to another method.
Since this is homework, I won't give you the full answer, but here is a way forward.
Instead of using the ref keyword, just pass the array into the method. Have the method return an int instead of void. Calculate the average within the method and have the final line of the method return the int that you've calculated
static int CalculateAverageScore(int[] playerScores)
{
// calculate average
return average; // the int you've calculated.
}
Call the method from the main, when you need to acquire the average.
Also, are you missing some braces { } for the 6 lines that come after your else statement?
I'm creating a simple game (Yatzee) in C#. I have created an array which holds 5 different dice
int[] dice = new int[5];
Now, I want to create a method that throw one of these five dices. Which die that should be thrown, should be passed in as an argument in that method. So this is how I tried:
public void throwDice(int x)
{
Random r1 = new Random(6);
r1.x;
}
What I believe is happening, is that the method takes in an argument x, that randomly should throw the dice to be a number between 1-6. But I'm getting error with when I write saying : r1.x;
So, why I'm asking here, is if I could get some guidance. Am I on the right track here, or am I totally lost?
You are using the Random object wrong. The constructor parameter is a seed. You need r1.Next(6)+1.
See the related post for details: How do I generate a random int number in C#?.
What you probably want to do is this:
Random rnd = new Random();
int[] dice = new int[5];
void ThrowDie(int x)
{
dice[x] = rnd.Next(6)+1;
}
r1 is an instance of a Random class. x is a parameter of your throwDice method.
That does not mean your r1 must have a field called x.
I think you are looking for something like;
Random r1 = new Random();
public int throwDice()
{
return r1.Next(1, 6);
}
Rememer, in Random.Next method lowerbound is inclusive but upperbound is exclusive.
Here is another approach to this matter:
public class RandomDice
{
private const int NUMBER_OF_DICE = 5;
private const int MAX_DICE_VALUE = 6;
private static readonly Random Rng = new Random();
public List<int> NumberList = new List<int>();
private static IEnumerable<int> GetRandomNumbers()
{
while (true)
yield return Rng.Next(1, MAX_DICE_VALUE + 1);
}
internal void AddDice()
{
NumberList.Clear();
NumberList.AddRange(GetRandomNumbers().Take(NUMBER_OF_DICE).ToList());
}
}