c# input only using slot 0 - c#

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();
}
}
}
}

Related

solution needed with a homework c# (cs7036)

I am trying to make a menu with different options on replit where the user can choose an option.
I am making the options on seperate files, so I later can call for the methods from those files instead of writing everything in the main file.
One of these menuoptions will have an option with a random generator which will generate a random string.
I created the method on another file, But when it gave me an error (7036) when i tried to call it to the main method.
I have pasted an example of the code here below, But you can also access and run the code on this link: https://replit.com/#AY2002/testc22#main.cs Which will be easier to understand. I am a begginer and, Therefore seeking a simple answer.
Thank you!
//MAIN replit FILE
using System;
using System.Collections.Generic;
namespace Namespace1 {
// This is the main file where the menu is built. the menu is working fine.
// the menu have 4 options and an exit option, which will be divided into 4 different replit files and one of them will have a method that randomly generates a string. you can see the method when you scroll down near to the bottom of the main file.
class Program {
public static void Main (string[] args)
{
string[] Menuchoises = new string [] {"Choise1","Choise2","Choise3","Choise4","Choise5"};
int x = 0;
while (true){
Console.Clear();
Console.WriteLine("welcome to menu");
Console.WriteLine();
Console.CursorVisible = false;
if(x == 0) {
Console.WriteLine(" " + Menuchoises[0] + " {");
Console.WriteLine(Menuchoises[1]);
Console.WriteLine(Menuchoises[2]);
Console.WriteLine(Menuchoises[3]);
Console.WriteLine(Menuchoises[4]);
}
else if(x == 1) {
Console.WriteLine(Menuchoises[0]);
Console.WriteLine(" " + Menuchoises[1] + " {");
Console.WriteLine(Menuchoises[2]);
Console.WriteLine(Menuchoises[3]);
Console.WriteLine(Menuchoises[4]);
}
else if(x == 2) {
Console.WriteLine(Menuchoises[0]);
Console.WriteLine(Menuchoises[1]);
Console.WriteLine(" " + Menuchoises[2] + " {");
Console.WriteLine(Menuchoises[3]);
Console.WriteLine(Menuchoises[4]);
}
else if(x == 3) {
Console.WriteLine(Menuchoises[0]);
Console.WriteLine(Menuchoises[1]);
Console.WriteLine(Menuchoises[2]);
Console.WriteLine(" " + Menuchoises[3] + " {");
Console.WriteLine(Menuchoises[4]);
}
else if(x == 4) {
Console.WriteLine(Menuchoises[0]);
Console.WriteLine(Menuchoises[1]);
Console.WriteLine(Menuchoises[2]);
Console.WriteLine(Menuchoises[3]);
Console.WriteLine("\t" + Menuchoises[4] + " {");
}
var key = Console.ReadKey();
if (key.Key == ConsoleKey.DownArrow && x != Menuchoises.Length -1) {
x++;
}
else if (key.Key == ConsoleKey.UpArrow && x>=1) {
x--;
} else if (key.Key == ConsoleKey.Enter) {
switch (x) {
case 0:
Menuchoise1();
break;
case 1:
Menuchoise2();
break;
case 2:
Menuchoise3();
break;
case 3:
Menuchoise4();
break;
case 4:
Menuchoise5();
break;
}
}
}
}
public static void Menuchoise1() {
// Class2.second is the name of the second class which will be the method that will appear when you choose the 1st option in the menu.
// The second class is in the second file which you`ll see below the main file
// The CS 7036 error seems to be appearing here
Class2.second();
Console.Clear();
Console.ReadKey();
}
public static void Menuchoise2() {
Console.Clear();
Console.ReadKey();
}
public static void Menuchoise3() {
Console.Clear();
Console.ReadKey();
}
public static void Menuchoise4() {
Console.Clear();
Console.ReadKey();
}
public static void Menuchoise5() {
Console.Clear();
Console.WriteLine("press enter to exit the menu");
Console.ReadKey();
Console.Clear();
Environment.Exit(1);
}
}
}
// SECOND replit FILE
//this is the second file where i have the random value generator.
using System;
using System.Collections.Generic;
namespace Namespace1 {
// class name of the second file
public class Class2 {
// the string[]args function that will later be put in the main file in order to use this method in the menu
public static string second(string[] Random) {
string[] RandomChoises = new string [4];
// list on options which will be randomly generated
RandomChoises[0] = "C1";
RandomChoises[1] = "C2";
RandomChoises[2] = "C3";
RandomChoises[3] = "C4";
RandomChoises[4] = "C5";
for (int i = 0; i < RandomChoises.Length; i++)
{
Console.WriteLine(RandomChoises[i]);
}
// the choises are randomly generated here
Random rnd = new Random();
int Randomanswer = rnd.Next(1,RandomChoises.Length);
Console.WriteLine("You got the answer: " + RandomChoises[Randomanswer]);
return Convert.ToString(Randomanswer);
}
}
}
As mentioned in the comments, the problem is that the second method takes a parameter, but is not called with one. Since the parameter is not used it should be removed. Cleaning up the class a bit should give you something like:
public static class RandomHelpers{
public static string GetRandomValue() {
// use collection initializer
string[] choices= new []{"C1","C2","C3","C4","C5"}
// use foreach loop
foreach(var choice in choices){
Console.WriteLine(choice );
}
// You should probably not recreate the random object for each method call
// But this should work fine for demonstration purposes
Random rnd = new Random();
// start from zero
int randomIndex = rnd.Next(0,RandomChoises.Length);
var randomValue = choices[randomIndex];
// You should probably just return the random value,
// and let the caller print it to console.
Console.WriteLine("You got the answer: " + randomValue );
// Either return the index as an int, or the value as a string
// Do not convert numbers to strings unless you are writing to the console/file
return randomValue ;
}
}
This should work better. As you get more experience you should find better ways to split functionality into reusable methods.
You have an issue with the way you are defining the array in second.cs. You either need explicitly say how many elements your array will have, like this:
string[] RandomChoice = new string[5];
Or you can leave the number out and let the compiler infer it from the number of elements you put in the {}, like this:
string[] RandomChoises = new string[] { "C1", "C2", "C3", "C4", "C5" };
You can read more details about declaring arrays in C# here: https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/arrays/
After you fix that see JonasH answer about the method parameters in second().

c#. array keeps resetting itself in my switch

I'm currently in programming 101 and I've been stuck for a long time with an issue.
My assignment wants me to create a class with a bunch of methods to run with a switch case( as a menu).
If I press 1 (add passenger), it does what it's supposed to do the first time, but the second time, it just restarts the array.
I can't seem to save my answer to the array and then move on to the next spot in the array.
Would someone please explain how I'm supposed to "call" the array and save in it outside my for-loop in method add_pass?
using System;
namespace bussen
{
class buss
{
public int[] passagerare;
public int numbof_passagerare;
public void Run()
{
int nmr = 0;
do
{
Console.WriteLine("options:");
Console.WriteLine("1 add passenger");
Console.WriteLine("2 print out all passengers");
Console.WriteLine("3 calc average age");
Console.WriteLine("0 close program");
nmr = int.Parse(Console.ReadLine());
switch (nmr)
{
case 1:add_pass();
break;
case 2:all_pass();
break;
case 3:
break;
case 0:
break;
}
} while (nmr != 0);
}
public void add_pass()
{
if (passagerare.Length < 5)
{
for (int i = 0; i < passagerare.Length; i++)
{
Console.WriteLine("type age of passenger");
int numbof_passenger = int.Parse(Console.ReadLine());
passagerare[i] = numbof_passenger;
break;
}
}
else if(passagerare.Length >= 5)
{
Console.WriteLine("buss is full");
}
}
public void all_pass()
{
foreach(int index in passagerare)
{
Console.WriteLine(index);
}
}
}
class Program
{
static void Main(string[] args)
{
var minbuss = new buss();
minbuss.Run();
Console.Write("Press any key to continue . . . ");
Console.ReadKey(true);
}
}
}
It's starting over because you're telling it to start over. The for loop starts at 0 every time.
for (int i = 0; i < passagerare.Length; i++)
{
Console.WriteLine("type age of passenger");
int numbof_passenger = int.Parse(Console.ReadLine());
passagerare[i] = numbof_passenger;
break;
}
You need to find the length of the array and append the new entry. Try using a List instead of any array.
The issue was within the add_pass method, where i used a for - loop to add passengers. each time i pressed number 1 in the menu to call the method , the loop restarted the array wich i was saving the integers to.To get this right i just called the method without a loop like shown below. Thanks everybody for your help!
public void add_pass()
{
if (numbof_passagerare < 5)
{
Console.WriteLine("how old is the passenger");
int age = int.Parse(Console.ReadLine());
passagerare[numbof_passagerare++] = age;
}
else if(numbof_passagerare == 5)
{
Console.WriteLine("buss is full!");
}

Why I can't able to get the User Input for The List Items through the Console Window?

I'm new to Programming. Now I have to learn C# List Items.
My Expectation:
Create an Empty List
Get the Input value for this list from the user through the console
Window.
My Program:
using System;
using System.Collections.Generic;
namespace Indexof_in_List
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Implementation of IndexOf Method with List");
Console.WriteLine();
//If the user entered empty value or nothing in the console window, the window will exit automatically
//Create an Empty List
List<int> name = new List<int>();
Console.WriteLine("Enter the Input values for the List");
//Get the Inputs for the List from the Console Window
for (int n = 0; n < name.Count; n++)
{
bool check;
string input = Console.ReadLine();
check = int.TryParse(input, out int val);
if (check)
{
name[n] = val;
}
else
{
Environment.Exit(0);
}
}
//Implement Index of any number in the list items which you have entered to the console
Console.WriteLine("The Index of value 10 is = {0}",name.IndexOf(10));
Console.WriteLine();
Console.WriteLine("The Index of value 1000 is ={0}", name.IndexOf(1000));
Console.WriteLine();
Console.ReadKey();
}
}
}
Output:
Could Anyone Tell me the solution for this C# Logic? And also tell me the reason for this failure?
And Tell me, whether my Logic is correct or not?
Your code has a few issues:
Count retrieves the current number of items in your list.
You have created your list using the default constructor, so the Capacity is also 0. Because of this you can't loop from 0 to name.Capacity.
You are trying to add items using an index. You can only access existing items using the name[index] syntax.
The simplest solution is to initialize the list as you are, and simply add items:
List<int> name = new List<int>();
for (int i = 0; i < 10; ++i)
{
bool check;
string input = Console.ReadLine();
check = int.TryParse(input, out int val);
if (check)
{
name.Add(val);
}
else
{
Environment.Exit(0);
}
}
This will read 10 numbers one after the other and add them to the list.
Thank you for your valuable Comments. Finally, I have done the final changes based on your feedback.
My Code:
using System;
using System.Collections.Generic;
namespace Indexof_in_List
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Implementation of IndexOf Method with List");
Console.WriteLine();
//Create an Empty List
List<int> name = new List<int>();
//If the user entered empty value or nothing in the console window, the window will exit automatically
Console.WriteLine("Enter the Input values for the List");
//Get the Inputs for the List from the Console Window
for (int n=0;n<5;n++)
{
bool check=false;
string input = Console.ReadLine();
check = int.TryParse(input, out int val);
if (check)
{
name.Add(val) ;
}
else
{
Environment.Exit(0);
}
}
if (name.Count != 0)
{
//Implement Index of any number in the list items which you have entered to the console
int index1 = name.IndexOf(10);
Console.WriteLine("The Index of value 10 is = {0}", name.IndexOf(10));
if (index1!=-1)
{
Console.WriteLine("The number 10 found in the List");
}
else
{
Console.WriteLine("The Number 10 found in the List");
}
int index2 = name.IndexOf(1000);
Console.WriteLine("The Index of value 1000 is ={0}", name.IndexOf(1000));
if (index2 != -1)
{
Console.WriteLine("The number 1000 found in the List");
}
else
{
Console.WriteLine("The Number 1000 not found in the List");
}
Console.WriteLine();
}
Console.ReadKey();
}
}
}

C# Need to set up a loop to reject invalid user input (below 1/ above 5) How can I do that? New to coding, making cinema entry app

namespace ConsoleApplication2
{
class Program
{
static void Main()
{
Console.WriteLine("Welcome to our Multiplex");
Console.WriteLine("We are presently Showing:");
Console.WriteLine("1.Legend");
Console.WriteLine("2.Macbeth");
Console.WriteLine("3.Everest");
Console.WriteLine("4.A Walk In the Woods");
Console.WriteLine("5.Hotel Transylvania");
Console.WriteLine("Enter the number of the film you wish to see?");
{
string moviestring = Console.ReadLine();
int movie = int.Parse(moviestring);
Here is solution I could suggest for your case:
static void Main(){
bool flag0 = true; //initialize tracking bool value to exit loop when needed
int result;
Console.WriteLine("Welcome to our Multiplex");
Console.WriteLine("We are presently Showing:");
Console.WriteLine("1.Legend");
Console.WriteLine("2.Macbeth");
Console.WriteLine("3.Everest");
Console.WriteLine("4.A Walk In the Woods");
Console.WriteLine("5.Hotel Transylvania");
do //do while loop suits this case best as it does check the value on the end
{
Console.WriteLine("Enter the number of the film you wish to see?");
string moviestring = Console.ReadLine();
int.TryParse(moviestring, out result); //does try-catch check so it wont crash on the run-time
if (result <= 5 && result >= 1) //logical check if value is correct
flag0 = false; //exits the loop
//do true logic....
else
Console.WriteLine("Incorrect value. Try again.");
//do false logic
} while (flag0);
}

ASP.NET MVC app: Debugging a function that returns "true" if input number is a Happy number using Lists vs Hashsets in array

So I'm working on an MVC view model that will tell a user if a given integer input is a Happy Number or not. As stated, the final code will sit in an MVC view model, but in the meantime, I've been checking the logic by debugging the code as a separate console app. I've got the console app working, but when I migrate the code back to the view model and then debug in the full application, literally nothing happens and IIS eventually times out the request. My view and controller implementations look solid (I'm leaving out that code for now), so I think I'm screwing up the logic in my actual model. Thoughts?
The code explained in further detail:
I'm new to OO programming, so for the sake of my own comprehension, I have split up the program into to two separate functions (Yes, I am aware this is bad practice, but it's homework). The first function (see below), which I've called "sumPowered", takes an integer input, separates the individual digits into an array, squares the individual digits, and returns the sum of the squared digits. Next, I have created a validation function called "isHappy" in which I call the preceding sumPowered function, pass through the parameters, generate a result array, and compare them to the happy number conditions.
To provide a clear outline, the first block of code below is the working code as it appears in my console app. The second block demonstrates how the code appears in the view model (doesn't work).
EDIT: I should have clarified that I am not producing any build errors or errors in the console view of Chrome's property inspector when I run the MVC code, yet the function did not work. I have since found a fix (answer post pending).
CONSOLE APP
//CONSOLE APP
namespace MoreCSharpPractice
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Enter a number");
int number = Convert.ToInt32(Console.ReadLine());
isHappy(number);
}
public static int sumPowered(int num, int pow)
{
int sum = 0;
List<int> numsL = new List<int>();
while (num > 0)
{
numsL.Add(num % 10);
num = num / 10;
}
int[] nums = numsL.ToArray();
for (int a = 0; a < nums.Length; a++)
{
sum += Convert.ToInt32(Math.Pow(Convert.ToDouble(nums[a]), Convert.ToDouble(pow)));
}
return sum;
}
//HAPPY NUMBER
//return true if 'number' is a happy number.
private static void isHappy(int number)
{
List<int> sumArray = new List<int>();
bool running = true;
while (running)
{
int result = sumPowered(number, 2);
if (result == 1)
{
running = false;
Console.WriteLine("Is a Happy Number!");
}
else if (sumArray.Contains(result))
{
running = false;
//return false;
Console.WriteLine("Is not a Happy Number");
}
number = result;
sumArray.Add(result);
}
//return true;
Console.ReadKey();
}
}
}
MVC CODE
//VIEW MODEL CODE: SUM POWERED FUNCTION
public static int sumPowered(int num, int pow)
{
int sum = 0;
List<int> numsL = new List<int>();
while (num > 0)
{
numsL.Add(num % 10);
num = num / 10;
}
int[] nums = numsL.ToArray();
for (int i = 0; i < nums.Length; i++)
{
sum += Convert.ToInt32(Math.Pow(Convert.ToDouble(nums[i]), Convert.ToDouble(pow)));
}
return sum;
}
//VIEW MODEL CODE: HAPPY NUMBER FUNCTION
//return true if 'number' is a happy number.
private static bool isHappy(int number)
{
List<int> sumArray = new List<int>();
while (true)
{
int result = sumPowered(number, 2);
if (result == 1)
{
return true;
}
else if (sumArray.Contains(result))
{
return false;
}
number = result;
sumArray.Add(result);
}
}
Determined that this wasn't a logic error but instead a performance issue while running debug. By changing the data type of variable sumArray in my isHappy() function from a List to a HashSet, I was able to run through the function without having to iterate through an entire list when invoking else if (sumArray.Contains(result)).
//HAPPY NUMBER
//return true if 'number' is a happy number.
private static bool isHappy(int number)
{
HashSet<int> sumArray = new HashSet<int>();
while (true)
{
int result = sumPowered(number, 2);
if (result == 1)
{
return true;
}
else if (sumArray.Contains(result))
{
return false;
}
number = result;
sumArray.Add(result);
}
}

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