Develop Reference

Console.Redline reading second line

I have a simple program that tells the user to input n amount of students, foreach student an x amount of money is allocated. At the end, the program divides x by n, meaning the total money is divided equally by the students.
The problem is that Console.Readline() is reading the second inputted value as see below.:
This means that the user has to enter the values two times, each time Console.Readline() is called, which is obviously wrong!
Code:
static void Main(string[] args)
{
double total = 0;
int noOfStudents = 0;
try
{
Console.WriteLine("Please enter the number of students :");
noOfStudents = checkInputTypeInt(Console.ReadLine());
Console.WriteLine("Enter the students(" + noOfStudents + ") money!");
for (int i = 0; i <= noOfStudents - 1; i++)
{
double money = checkInputTypeDouble(Console.ReadLine());
total += money;
}
double dividedTotal = total / noOfStudents;
Console.WriteLine("Total divided by " + noOfStudents + " is $ " + dividedTotal.ToString("F2"));
Console.ReadKey();
}
catch(Exception e)
{
Console.WriteLine(e);
}
}
private static int checkInputTypeInt(string s)
{
int numericValue = 0;
bool done = false;
while (!done)
{
if (!int.TryParse(Console.ReadLine(), out numericValue))
Console.WriteLine("The input must be between 0 and 1000!");
else if (numericValue > 100)
Console.WriteLine("The input must be between 0 and 1000!");
else
done = true;
}
return numericValue;
}

You ReadLine twice:
noOfStudents = checkInputTypeInt(Console.ReadLine());
and in checkInputTypeInt method:
if (!int.TryParse(Console.ReadLine(), out numericValue))
You should either send only the string to method like this:
noOfStudents = checkInputTypeInt(Console.ReadLine());
and in your method just check that value like:
if (!int.TryParse(s, out numericValue))
in this case you should have the while loop in your main method.
or just use readline in the called method.
Console.WriteLine("Please enter the number of students :");
noOfStudents = checkInputTypeInt(); // and you should change your method to fit no arguments.
Edit: final codes:
static void Main(string[] args)
{
double total = 0;
int noOfStudents = 0;
try
{
Console.WriteLine("Please enter the number of students :");
noOfStudents = checkInputTypeInt();
Console.WriteLine("Enter the students(" + noOfStudents + ") money!");
for (int i = 0; i <= noOfStudents - 1; i++)
{
double money = checkInputTypeDouble(Console.ReadLine());
total += money;
}
double dividedTotal = total / noOfStudents;
Console.WriteLine("Total divided by " + noOfStudents + " is $ " + dividedTotal.ToString("F2"));
Console.ReadKey();
}
catch(Exception e)
{
Console.WriteLine(e);
}
}
private static int checkInputTypeInt()
{
int numericValue = 0;
bool done = false;
while (!done)
{
if (!int.TryParse(Console.ReadLine(), out numericValue))
Console.WriteLine("The input must be between 0 and 1000!");
else if (numericValue > 100)
Console.WriteLine("The input must be between 0 and 1000!");
else
done = true;
}
return numericValue;
}
OR:
static void Main(string[] args)
{
double total = 0;
int noOfStudents = -1;
try
{
Console.WriteLine("Please enter the number of students :");
do{
noOfStudents = checkInputTypeInt(Console.ReadLine());
}while(noOfStudents == -1);
Console.WriteLine("Enter the students(" + noOfStudents + ") money!");
for (int i = 0; i <= noOfStudents - 1; i++)
{
double money = checkInputTypeDouble(Console.ReadLine());
total += money;
}
double dividedTotal = total / noOfStudents;
Console.WriteLine("Total divided by " + noOfStudents + " is $ " + dividedTotal.ToString("F2"));
Console.ReadKey();
}
catch(Exception e)
{
Console.WriteLine(e);
}
}
private static int checkInputTypeInt(string s)
{
int numericValue = -1;
if (!int.TryParse(Console.ReadLine(), out numericValue))
Console.WriteLine("The input must be between 0 and 1000!");
else if (numericValue > 1000)
{Console.WriteLine("The input must be between 0 and 1000!");
numericValue = -1;
}
return numericValue;
}

Try to divide the noOfStudents and Console.ReadLine() like this:
int i = Convert.ToInt32(Console.ReadLine());
noOfStudents = i;

C# :Adapt a program to count the number of marks greater than or equal to 50

my code is where the user needs to enter a mark between and then if the mark is not between 0 and 100, it must ask again, i got that to work , but now the question states : Adapt the above program to also count the number of marks greater than or equal to 50.
How do I do this , I have tried declaring count an integer 0 but I am unsure how
to implement this.
Here is my code:
static void Main(string[] args)
{
int total = 0;
for (int x = 1; x <= 5; x++)
{
Console.WriteLine("Enter your mark");
int mark = int.Parse(Console.ReadLine());
if (mark > 100 || mark < 0)
{
Console.WriteLine("Invalid mark,Enter your mark again");
int newmark = int.Parse(Console.ReadLine());
mark = newmark;
}
total += mark;
}
Console.WriteLine("sum = " + total);
double average = (total / 5) * 1.00;
Console.WriteLine("average = " + average);
Console.ReadLine();
}

First of all, I suggest extracting a method: do not cram everything into a single Main:
private static int readMark() {
Console.WriteLine("Enter your mark");
int result = 0;
while (true)
if (!int.TryParse(Console.ReadLine(), out result))
Console.WriteLine("Incorrect syntax, enter your mark again");
else if (result < 0 || result > 100)
Console.WriteLine("Mark should be in [0..100] range, enter your mark again");
else
return result;
}
Then let's read all the marks into a collection, say, an array:
static void Main(string[] args) {
int[] marks = new int[5];
for (int i = 0; i < marks.Length; ++i)
marks[i] = readMark();
}
Now it's time for the statistics. Usually we use Linq for this:
static void Main(string[] args) {
...
double average = marks.Average();
int sum = marks.Sum();
int countGreaterThan50 = marks.Count(item => item > 50);
But we can put a good old for / foreach loop for this:
static void Main(string[] args) {
...
int total = 0;
countGreaterThan50 = 0;
for (int i = 0; i < marks.Length; ++i) {
total += marks[i];
if (marks[i] > 50)
countGreaterThan50 += 1;
}
// (double) total - be careful with integer division:
// 91 / 5 == 18 when 91.0 / 5 == 18.2
double average = ((double) total) / marks.Length;

static void Main(string[] args)
{
int total = 0;
int gt50Count = 0;
for (int x = 1; x <= 5; x++)
{
Console.WriteLine("Enter your mark");
int mark = int.Parse(Console.ReadLine());
if (mark > 100 || mark < 0)
{
Console.WriteLine("Invalid mark,Enter your mark again");
int newmark = int.Parse(Console.ReadLine());
mark = newmark;
}
total += mark;
if (mark >= 50)
{
gt50Count++;
}
}
Console.WriteLine("sum = " + total);
double average = (total / 5) * 1.00;
Console.WriteLine("average = " + average);
Console.WriteLine("Greater or equal to 50 count = " + gt50Count);
Console.ReadLine();
}

I would change the way you check if your mark is invalid to a while loop. With just that if check, if the user inserts invalid values consecutively, your code will accept it.
static void Main(string[] args)
{
int total = 0;
int marksAbove50Count = 0;
for (int x = 1; x <= 5; x++)
{
Console.WriteLine("Enter your mark");
int mark = int.Parse(Console.ReadLine());
while (mark > 100 || mark < 0)
{
Console.WriteLine("Invalid mark,Enter your mark again");
int newmark = int.Parse(Console.ReadLine());
mark = newmark;
}
total += mark;
if(mark >= 50) marksAbove50Count++;
}
Console.WriteLine("sum = " + total);
double average = (total / 5) * 1.00;
Console.WriteLine("average = " + average);
Console.WriteLine("Marks above 50 count: " + marksAbove50Count);
Console.ReadLine();
}

do/while and if/else problems

I have to put in an extra "test score" to get an answer.
(i.e i have to enter six 5' to get 25)
I can't get the do/while & if statements to loop if there is more than one number outside the "while" range. I haven't been coding for very long, a couple weeks so try and break down the answers. Thanks for the help!
Here is my code
Console.Write("Enter the number of tests: ");
int n = int.Parse(Console.ReadLine());
int[] scores = new int[n];
Console.WriteLine("----------------------------------------");
Console.WriteLine("Please enter the test scores");
int i;
do
{
i = Convert.ToInt32(Console.ReadLine());
if (i < 0)
{
Console.WriteLine("Please enter a value greater than 0");
}
if (i > 100)
{
Console.WriteLine("Please enter a value less than 100");
}
} while (i < 0 || i > 100);
for (i = 0; i < n; i++)
{
scores[i] = int.Parse(Console.ReadLine());
}
int sum = 0;
foreach (int d in scores)
{
sum += d;
}
Console.WriteLine("The sum of all the scores is {0}",sum);
Console.ReadLine();

Put the do block that does the input validation inside the for loop:
Console.Write("Enter the number of tests: ");
int n = int.Parse(Console.ReadLine());
int[] scores = new int[n];
Console.WriteLine("----------------------------------------");
Console.WriteLine("Please enter the test scores");
for (int i = 0; i < n; i++)
{
int input = -1;
do
{
input = Convert.ToInt32(Console.ReadLine());
if (input < 0)
{
Console.WriteLine("Please enter a value greater than 0");
}
else if (input > 100)
{
Console.WriteLine("Please enter a value less than 100");
}
} while (input < 0 || input > 100);
scores[i] = input;
}
int sum = 0;
foreach (int d in scores)
{
sum += d;
}
Console.WriteLine("The sum of all the scores is {0}", sum);
Console.ReadLine();

n is the number of tests, meaning the amount of scores counter i should be the same as the amount of tests. Also prefer Convert.ToInt32 to int.Parse since it throws exceptions in case it isn't able to make the conversion.
Console.Write("Enter the number of tests: ");
int n = Convert.ToInt32(Console.ReadLine());
int sum = 0, i = 0, score = 0;
int[] scores = new int[n];
Console.WriteLine("----------------------------------------");
do {
Console.WriteLine("Please enter the test score #" + (i + 1));
score = Convert.ToInt32(Console.ReadLine());
if (score < 0) {
Console.WriteLine("Please enter a value greater or equal to 0");
}
else if (score > 100)
{
Console.WriteLine("Please enter a value less or equal to 100");
}
else {
scores[i] = score;
i++;
}
} while (i < n);
foreach (int d in scores) {
sum += d;
}
Console.WriteLine("The sum of all the scores is {0}", sum);
Console.ReadLine();

Just for the potential learning opportunity, and and not as a direct answer to your question, here is the way I would do this exercise:
Console.Write("Enter the number of tests: ");
int n = int.Parse(Console.ReadLine());
Console.WriteLine("----------------------------------------");
Console.WriteLine("Please enter the test scores");
int AskForInteger()
{
while (true)
{
if (int.TryParse(Console.ReadLine(), out int i) && i >= 0 && i <= 100)
{
return i;
}
Console.WriteLine("Please enter a value between 0 and 100 inclusive");
}
}
int[] scores =
Enumerable
.Range(0, n)
.Select(x => AskForInteger())
.ToArray();
Console.WriteLine("The sum of all the scores is {0}", scores.Sum());
Console.ReadLine();

There are two options:
a. Start at 1 rather than 0 --> for (i = 1; i < n; i++)
b. Lower the value of n by 1 --> for (i = 1; i < n-1; i++)
Good luck

C# -sum of two numbers, then ask for new number again and add

new to C# and programming and been practicing on loops.
Im trying to build a program that will initially ask for 2 numbers, then it will output the sum, then will ask for another number again, then add to the previous result.
The loop will only stop when the user input 00.
Here is the code that i thought of, apologies for the poor coding yet. ><
Please suggest/use any loop that you may think that is efficient for this. Thanks!
public static void getnum()
{
Console.Write("Enter number: ");
int num = Int32.Parse(Console.ReadLine());
Console.Write("Enter number: ");
int num2 = Int32.Parse(Console.ReadLine());
}
static void Main(string[] args)
{
getnum();
while (num!=00)
{
getnum();
int sum = num + num2;
Console.WriteLine("Sum is: " + sum);
}
Console.Read();

You can simplify it something like this
static void Main(string[] args)
{
int sum = 0;
string currentNumber = "0";
while (currentNumber!="00")
{
int num = Int32.Parse(currentNumber);
sum += num;
Console.WriteLine("Sum is: " + sum);
currentNumber = Console.ReadLine();
}
Console.Read();
}

Here is a sample which does what you want:
var answer = 0;
var num = 0;
var num2 = 0;
while(answer!=1)
{
Console.Write("Enter number: ");
num = Int32.Parse(Console.ReadLine());
Console.Write("Enter number: ");
num2 = Int32.Parse(Console.ReadLine());
var sum = num + num2;
Console.WriteLine("Sum is: " + sum);
Console.Write("Press 1 to exit or 2 to continue: ");
answer = Int32.Parse(Console.ReadLine());
};

This code will work.
class Program
{
static int num1 = 0;
static int num2 = 0;
public static void getnum()
{
Console.Write("Enter number: ");
num1 = Int32.Parse(Console.ReadLine());
Console.Write("Enter number: ");
num2 = Int32.Parse(Console.ReadLine());
}
static void Main(string[] args)
{
getnum();
//This is the loop.
do
{
ShowNum();
getnum();
} while (num1 != 00);
}
static void ShowNum()
{
int sum = num1 + num2 ;
//Here we show the Sum.
Console.WriteLine("Sum is: " + sum.ToString());
}
}

You can try this too
string input = "";
int Sum = 0, newNumber;
while (input != "00")
{
Console.Write("Enter number(press 00 to print the sum): ");
input = Console.ReadLine();
if (!Int32.TryParse(input, out newNumber))
{
Console.WriteLine("Input is not a valid number; 0 is taken as default value");
}
Sum += newNumber;
}
Console.WriteLine(" Sum of entered numbers {0}",Sum);
Console.ReadKey();

You need two things.
Read atleast two numbers.
Sum input numbers until user press '00'
.
public static void Main()
{
int numCount = 0;
int sum = 0;
string input;
do
{
Console.Write("Enter number: ");
input = Console.ReadLine();
int num;
if (int.TryParse(input, out num))
{
sum += num;
numCount++;
Console.WriteLine("Sum is: " + sum);
}
} while (!(numCount > 2 && input == "00")); // Make sure at least two numbers and until user rpess '00'
}
Working Demo

You can also try with this
int input = 0;
int total = 0;
while (true)
{
Console.WriteLine("Enter a number (Write Ok to end): ");
string write = Console.ReadLine();
if (write == "Ok")
{
break;
}
else
{
input = int.Parse(write);
total = total + input;
}
Console.WriteLine("Total: " + total);
}

C# mastermind game

In the Main method, in the for loop, if you copy/paste/run whole program in visual, you'll see that i'm trying to end the game. First "if", if the user hasn't guessed; then attempts decrements by one and keeps guessing. The second "else if", if the user has guessed the PCArray, than the game ends and message shows. those work.
But, the first "else if", if the user has exhausted his attempts to guess, and hasn't guessed PCArray, than it should say "oh no, you couldn't guess..." Why is this not working.
I just want it to work so that if:
- user hasn't guessed but still has attempts, attempts decrements by 1 until 0.
- user has guessed the correct number, it says congrats.
- attempts are 0 and user still hasn't guessed number, then show "oh no..." message.
class Program
{
static void Main(string[] args)
{
string name;
Console.WriteLine("**************Let's play Master-Mined**************");
Console.WriteLine();
Console.Write("Please enter your name: ");
name = Console.ReadLine();
Console.WriteLine("Welcome {0}. Have fun!! ", name);
int numberCount = 0;
int difficultyLevel = 0;
int digitNumber = GetRandomNumberCount(numberCount);
Console.Write(digitNumber + " it is. Let's play.");
Console.WriteLine();
int[] PCArray = GenerateRandomNumbers(digitNumber);
Console.WriteLine("A " + digitNumber + "-digit number has been chosen. Each possible digit may be the number 1, 2, 3 or 4.");
Console.WriteLine(" ******");
int difficulty = GetGameDifficulty(difficultyLevel);
int attempts = difficulty * digitNumber;
Console.WriteLine("Enter your guess ({0} guesses remaining)", attempts);
int remaining = attempts;
for (int i = 0; i < attempts; i++)
{
int[] userArray = GetUserGuess(digitNumber);
int hits = CountHits(PCArray, userArray, attempts);
if ((hits != PCArray.Length) && (attempts > 0))
{
remaining--;
Console.WriteLine("Enter your guess ({0} guesses remaining)", remaining);
}
else if ((attempts < 1))
{
Console.WriteLine("Oh no {0}! You couldn't guess the right number.", name);
Console.WriteLine("The correct number is: ");
for (int j = 0; j < PCArray.Length; j++)
{
Console.Write(PCArray[j] + " ");
}
Console.WriteLine("Would you like to play again (Y/N)? ");
}
else if (hits == PCArray.Length)
{
attempts = 0;
Console.WriteLine("You win {0}!", name);
Console.WriteLine("The correct number is:");
for (int j = 0; j < PCArray.Length; j++)
{
Console.Write(PCArray[j] + " ");
}
}
}
Console.ReadLine();
}
public static int GetRandomNumberCount(int numberCount)
{
int number = 0;
do
{
try
{
Console.Write("How many numbers would you like to use in playing the game (4-10)? ");
number = int.Parse(Console.ReadLine());
Console.WriteLine();
}
catch
{
Console.WriteLine("You must pick a number between 4 and 10. Choose again.");
Console.WriteLine();
}
} while ((number < 4) || (number > 10));
return number;
}
public static int GetGameDifficulty(int difficultyLevel)
{
int difficulty = 0;
do
{
try
{
Console.Write("Choose a difficulty level (1=hard, 2=medium, 3=easy): ");
difficulty = int.Parse(Console.ReadLine());
}
catch
{
Console.WriteLine(" Incorrect entry: Please re-enter.");
}
} while ((difficulty < 1) || (difficulty > 3));
return difficulty;
}
public static int[] GenerateRandomNumbers(int PCSize)
{
int eachNumber;
int[] randomNumber = new int[PCSize];
Random rnd = new Random();
for (int i = 0; i < randomNumber.Length; i++)
{
eachNumber = rnd.Next(1, 5);
randomNumber[i] = eachNumber;
Console.Write(eachNumber);
}
Console.WriteLine();
return randomNumber;
}
public static int[] GetUserGuess(int userSize)
{
int number = 0;
int[] userGuess = new int[userSize];
for (int i = 0; i < userGuess.Length; i++)
{
Console.Write("Digit {0}: ", (i + 1));
number = int.Parse(Console.ReadLine());
userGuess[i] = number;
//Console.Write(number);
}
Console.WriteLine();
Console.Write("Your guess: ");
for (int i = 0; i < userGuess.Length; i++)
{
Console.Write(userGuess[i] + " ");
}
Console.WriteLine();
return userGuess;
}
public static int CountHits(int[] PCArray, int[] userArray, int attempts)
{
int hit = 0;
int miss = 0;
int hits = 0;
for (int i = 0; i < PCArray.Length; i++)
{
if (PCArray[i] == userArray[i])
{
hit = hit + 1;
hits = hit;
}
else
{
miss = miss + 1;
}
}
Console.WriteLine("Results: {0} Hit(s), {1} Miss(es)", hit, miss);
return hits;
}
}

First of all, you should rethink your code, because the flow control is scattered throughout your code. For example, you don't need both attempts and remaining, they control the same thing.
Using two variables to control the same thing is what is causing your problem. The first two ifs in your for should be like this:
if (hits != PCArray.Length && remaining > 1)
and
else if (remaining == 1)
Note I removed the unnecessary parenthesis. With these changes, your application works, although the code is not too pretty.
A simple way of enhancing your code is to first check for the right result, and if it's not, then decrease the attempts variable and finally check for its value. That's why with your code as it is, the if should compare to 1 instead of 0.
The hits variable in your CountHits method is totally unnecessary; you should just return hit. Actually the miss variable can be avoided too, you can calculate it. Also remember to use the ++ operator.
But as I said first, the important thing is not to make it work but to organize your code properly. Later I will post my version.
My version, it's not the most beautiful thing in the world but I didn't want to change much of your code structure:
class Program
{
static void Main(string[] args)
{
Console.WriteLine("************** Let's play Master-Mind **************\n");
string name = GetPlayerName();
do
{
Play(name);
Console.Write("\nWould you like to play again (Y/N)? ");
}
while (Console.ReadLine().ToUpper() == "Y");
}
private static void Play(string name)
{
int numberCount = GetRandomNumberCount();
Console.Write(numberCount + " it is. Let's play.");
Console.WriteLine();
int[] PCArray = GenerateRandomNumbers(numberCount);
Console.WriteLine("A {0}-digit number has been chosen. Each possible digit may be the number 1 to 4.\n", numberCount);
int difficulty = GetGameDifficulty();
bool won = false;
for (int allowedAttempts = difficulty * numberCount; allowedAttempts > 0 && !won; allowedAttempts--)
{
Console.WriteLine("\nEnter your guess ({0} guesses remaining)", allowedAttempts);
int[] userArray = GetUserGuess(numberCount);
if (CountHits(PCArray, userArray) == numberCount)
won = true;
}
if (won)
Console.WriteLine("You win, {0}!", name);
else
Console.WriteLine("Oh no, {0}! You couldn't guess the right number.", name);
Console.Write("The correct number is: ");
for (int j = 0; j < numberCount; j++)
Console.Write(PCArray[j] + " ");
Console.WriteLine();
}
private static string GetPlayerName()
{
Console.Write("Please enter your name: ");
string name = Console.ReadLine();
Console.WriteLine("Welcome, {0}. Have fun!!\n", name);
return name;
}
public static int GetRandomNumberCount()
{
int number;
Console.Write("How many numbers would you like to use in playing the game (4-10)? ");
while (!int.TryParse(Console.ReadLine(), out number) || number < 4 || number > 10)
Console.WriteLine("You must pick a number between 4 and 10. Choose again.");
return number;
}
public static int GetGameDifficulty()
{
int difficulty = 0;
Console.Write("Choose a difficulty level (1=hard, 2=medium, 3=easy): ");
while (!int.TryParse(Console.ReadLine(), out difficulty) || difficulty < 1 || difficulty > 3)
Console.WriteLine("Incorrect entry: Please re-enter.");
return difficulty;
}
public static int[] GenerateRandomNumbers(int PCSize)
{
int eachNumber;
int[] randomNumber = new int[PCSize];
Random rnd = new Random();
Console.Write("PC number: ");
for (int i = 0; i < PCSize; i++)
{
eachNumber = rnd.Next(1, 5);
randomNumber[i] = eachNumber;
Console.Write(eachNumber);
}
Console.WriteLine();
return randomNumber;
}
public static int[] GetUserGuess(int userSize)
{
int number = 0;
int[] userGuess = new int[userSize];
for (int i = 0; i < userSize; i++)
{
Console.Write("Digit {0}: ", (i + 1));
while (!int.TryParse(Console.ReadLine(), out number) || number < 1 || number > 4)
Console.WriteLine("Invalid number!");
userGuess[i] = number;
}
Console.WriteLine();
Console.Write("Your guess: ");
for (int i = 0; i < userSize; i++)
{
Console.Write(userGuess[i] + " ");
}
Console.WriteLine();
return userGuess;
}
public static int CountHits(int[] PCArray, int[] userArray)
{
int hits = 0;
for (int i = 0; i < PCArray.Length; i++)
{
if (PCArray[i] == userArray[i])
hits++;
}
Console.WriteLine("Results: {0} Hit(s), {1} Miss(es)", hits, PCArray.Length - hits);
return hits;
}
}
It does a few more validations and it even actually lets you play again! ;)