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C# Loop back to a previous part of code

//Gender Creation:
while (correct == 0)
{
do
{
Console.Clear();
Console.WriteLine("Please choose a gender from the options below: ");
Console.WriteLine("Male|Female|Random");
Console.Write("Input: ");
Gender = Console.ReadLine().ToUpper();
if (Gender == "MALE")
{
Console.WriteLine("Is this the gender you wish your character to be? Enter Yes/No: ");
Console.Write("Input: ");
Input = Console.ReadLine().ToUpper();
if (Input == "YES")
{
correct = 1;
}
else if (Input == "NO")
{
correct = 0;
}
}
else if (Gender == "FEMALE")
{
Console.WriteLine("Is this the gender you wish your character to be? Enter Yes/No: ");
Console.Write("Input: ");
Input = Console.ReadLine().ToUpper();
if (Input == "YES")
{
correct = 1;
}
else if (Input == "NO")
{
correct = 0;
}
}
else if (Gender == "RANDOM")
{
correct = 2;
}
else
{
Console.WriteLine("ERROR, Please try again.");
Gender = Console.ReadLine().ToUpper();
}
} while (correct == 0);
//Random Gender Creation:
if (correct == 2)
{
do
{
if (randgender == 1)
{
Console.WriteLine("The gender: MALE was randomly chosen");
Console.WriteLine("Is this the gender you wish your character to be? Enter Yes/No: ");
Console.Write("Input: ");
Input = Console.ReadLine().ToUpper();
if (Input == "YES")
{
correct = 1;
Gender = "MALE";
}
else if (Input == "NO")
{
correct = 2;
}
}
else if (randgender == 2)
{
Console.WriteLine("The gender: FEMALE was randomly chosen");
Console.WriteLine("Is this the race you wish your character to be? Enter Yes/No: ");
Console.Write("Input: ");
Input = Console.ReadLine().ToUpper();
if (Input == "YES")
{
correct = 1;
Gender = "FEMALE";
}
else if (Input == "NO")
{
correct = 2;
}
}
} while (correct == 2);
correct = 0;
}
break;
}
When correct = 2 then the gender is being randomly generated, if the user inputs no when being asked if they are happy with the gender the code will just loop the random gender generator over and over constantly saying that the random gender is the same every time as the random number is never changing however when correct = 0 the code will just proceed when no is inputted and when the gender is printed it is just printed as RANDOM as that is the option the user initially chose.
How can I make it go back to the first do while loop to ask the user what gender they want their character to be?

As theMayer suggested, you'll need to break down your app into smaller pieces. There are also a few concepts that you may need to tackle before you can write C#, as such.
This example might help you get a little further along, as it illustrates several ways of achieving better control flow:
static void Main(string[] args)
{
Console.Clear();
var choosenGender = "";
var wasChoiceConfirmed = false;
while (wasChoiceConfirmed == false)
{
choosenGender = PromptForGender();
switch (choosenGender)
{
case "RANDOM":
var randomGender = GenerateRandomGender();
wasChoiceConfirmed = PromptForGenderConfirmation(randomGender, true);
break;
case "MALE":
case "FEMALE":
wasChoiceConfirmed = PromptForGenderConfirmation(choosenGender);
break;
default:
Console.WriteLine("Error, please try again. \n");
break;
}
}
}
static string PromptForGender()
{
Console.Write(
"\nPlease choose a gender from the options below: \n" +
"Male|Female|Random \n" +
"Input:");
return Console.ReadLine().Trim().ToUpper();
}
static bool PromptForGenderConfirmation(string gender, bool wasRandom = false)
{
var randomVerbiage = wasRandom ? "randomly " : "";
Console.Write(
$"\nThe gender: {gender} was {randomVerbiage}chosen \n" +
"Is this the gender you wish your character to be? Enter Yes/No: \n" +
"Input: ");
var confirmed = Console.ReadLine().Trim().ToUpper();
return confirmed == "YES";
}
static string GenerateRandomGender()
{
var randomNumber = new Random();
return randomNumber.Next(0, 1) == 0 ? "FEMALE" : "MALE";
}

I refactored your code so it helps me understand it better. This gives you the result you want and you don't need all those nested loops.
public class Program
{
public static void AskFirstQuestion()
{
Console.Clear();
Console.WriteLine("Please choose a gender from the options below: ");
Console.WriteLine("Male|Female|Random");
Console.Write("Input: ");
var gender = Console.ReadLine()?.ToUpper();
if (gender == "MALE" || gender == "FEMALE")
{
HandleGenderSelection(gender);
}
else if (gender == "RANDOM")
{
HandleRandom();
}
}
private static void HandleRandom()
{
var randomGender = GenerateRandomGender();
Console.WriteLine($"The gender: {randomGender} was randomly chosen");
Console.WriteLine("Is this the race you wish your character to be? Enter Yes/No: ");
Console.Write("Input: ");
var input = Console.ReadLine()?.ToUpper();
switch (input)
{
case "YES":
Console.WriteLine("OK");
break;
case "NO":
AskFirstQuestion();
break;
}
}
private static string GenerateRandomGender()
{
//Have you logic to randomly create gender
return "MALE";
}
private static void HandleGenderSelection(string gender)
{
Console.WriteLine("Is this the gender you wish your character to be? Enter Yes/No: ");
Console.Write("Input: ");
var input = Console.ReadLine()?.ToUpper();
if (input == "YES")
{
Console.WriteLine("OK!");
}
else if (input == "NO")
{
AskFirstQuestion();
}
}
static void Main(string[] args)
{
AskFirstQuestion();
}
}

how to only have numbers stored in an string array in console application

So, I am trying to create a pizza ordering program for my school project which requires the customer/user to input their details e.g name phone number address and what not. I store all those information into a string array, but how to I only allow numbers to be entered into the phone number section. I tried using a method which I have been provided with but it doesn't seem to work it just errors.
Here is my current code
public static string[] GetCustInfo(string [] custInfo)
{
start:
bool success = false;
Console.Write("\n" + "Please input D for Delivery OR P for Pickup($3 for Delivery): " + "\n");
custInfo[0] = Console.ReadLine();
while (success != true)
{
if (custInfo[0] == "D" || custInfo[0] == "d")
{
custInfo[1] = ReadString("Please enter your name: ");
Console.Write(Readint("Please enter your Ph No. : "));
custInfo[2] = Console.ReadLine();
custInfo[3] = ReadString("Please enter your adress: ");
success = true;
}
else if (custInfo[0] == "P" || custInfo[0] == "p")
{
custInfo[1] = ReadString("Please enter your name: ");
success = true;
}
else
{
goto start;
}
}
return custInfo;
}
Here are the methods I am using to prevent the user from entering a number or letter:
public static int Readint(String prompt)
{
int userInput = 0;
Boolean success = false;
while (!success)
{
Console.Write(prompt);
try
{
userInput = Convert.ToInt32(Console.ReadLine());
success = true;
}
catch
{
Console.WriteLine("Please Enter a VALID NUMBER");
}
}
return userInput;
}
public static string ReadString(String prompt)
{
string userInput = " ";
Boolean success = false;
while (!success)
{
Console.Write(prompt);
try
{
userInput = Console.ReadLine();
if (userInput.Length <= 20 && userInput.Length>1)
{
success = true;
foreach (char charcter in userInput)
{
if (Char.IsNumber(charcter) || Char.IsSymbol(charcter) || Char.IsPunctuation(charcter))
{
success = false;
}
}
}
if (success == false)
{
Console.WriteLine("Please enter a valid input!" + "\n");
}
else
{
success = true;
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
return userInput;
}
I tried inserting:
custInfo[2] = Readint("Please enter your Ph No.");
but it just gave me an error saying:
"cannot implicate type int to string"

but how to I only allow numbers to be entered into the phone number
You ReadInt method already takes care of this point with the while-loop and the try/catch clause. If you want to store this information into the array you need to get your number into the correct/fitting data type for the array saying: string. You return value of ReadInt is an int and this class has an implementation of the ToString method which in your case would convert the int into a string. So you can simply call it on the returnvalue of ReadInt:
custInfo[1] = ReadString("Please enter your name: ");
custInfo[2] = Readint("Please enter your Ph No.").ToString();
custInfo[3] = ReadString("Please enter your adress: ");

Insted of public static string[] GetCustInfo(string [] custInfo), you might add array of an objects, but keep in mind next : Object array store elements of different types in a single collection. An object reference can point to any derived type instance.
Whatever you could do this :
object[] array1 = new object[5];
array1[0] = new object();
array1[1] = new StringBuilder("Initialized");
array1[2] = "String literal";
array1[3] = 3;
array1[4] = null;
So in your case: this might look like this
public static object[] GetCustInfo(object [] custInfo)

You trying to insert an int value into string array..surely make sense that you convert the value into a string?

Return to Start/Top in C # console application

I am trying to go back to start in c# console program, and i am somehow able to do it, but the problem is that i am not able to do it using the Y/N statement. mean if i type the Y (yes) from keyboard then the program start from it's starting (beginning) point if i type N then it will terminate the program.
My Console code is:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace simple_calculation
{
class Program
{
static void Main(string[] args)
{
bool bktop = true;
string option;
while (bktop)
{
Console.WriteLine("Please enter the values");
int val = int.Parse(Console.ReadLine());
int val1 = int.Parse(Console.ReadLine());
int res = val + val1;
int red = val / val1;
Console.WriteLine("Please enter the operator");
string oper=Console.ReadLine();
if (oper == "+")
{
Console.WriteLine("sum is:" + res);
}
else if (oper == "/")
{
Console.WriteLine("division is:" + red);
}
else
{
Console.WriteLine("do you want to continue? enter Y/N");
option = Console.ReadLine();
if(option=="Y")
{
bktop = false;
}
else
{
bktop = true;
}
}
Console.ReadLine();
}
}
}
}
What I want: i want that when the program reaches to the else condition then there is a text appear in the console "do you want to continue? enter Y/N" if the user enter Y then the program start again and if the user enter N then the program will terminate.
Any help will be appreciated.

class Program
{
static void Main(string[] args)
{
// Change 1
bool bktop = true;
string option;
while (bktop)
{
bktop = true;
Console.WriteLine("Please enter the values");
int val = int.Parse(Console.ReadLine());
int val1 = int.Parse(Console.ReadLine());
int res = val + val1;
int red = val / val1;
Console.WriteLine("Please enter the operator");
string oper = Console.ReadLine();
if (oper == "+")
{
Console.WriteLine("sum is:" + res);
}
else if (oper == "/")
{
Console.WriteLine("division is:" + red);
}
else
{
Console.WriteLine("do you want to continue? enter Y/N");
option = Console.ReadLine();
// Change 2
if (option.ToUpper() != "Y")
{
bktop = false;
}
}
}
}
}

How do I only allow number input into my C# Console Application?

Console.WriteLine("Enter the cost of the item");
string input = Console.ReadLine();
double price = Convert.ToDouble(input);
Hello, I want the keyboard buttons, A-Z, brackets, question mark, etc to be disabled. I want it so if you type it in, it will not show up in the Console. I only want the numbers 1-9 to show up. This is in C# Console application. Thanks for the help!

try this code snippet
string _val = "";
Console.Write("Enter your value: ");
ConsoleKeyInfo key;
do
{
key = Console.ReadKey(true);
if (key.Key != ConsoleKey.Backspace)
{
double val = 0;
bool _x = double.TryParse(key.KeyChar.ToString(), out val);
if (_x)
{
_val += key.KeyChar;
Console.Write(key.KeyChar);
}
}
else
{
if (key.Key == ConsoleKey.Backspace && _val.Length > 0)
{
_val = _val.Substring(0, (_val.Length - 1));
Console.Write("\b \b");
}
}
}
// Stops Receving Keys Once Enter is Pressed
while (key.Key != ConsoleKey.Enter);
Console.WriteLine();
Console.WriteLine("The Value You entered is : " + _val);
Console.ReadKey();

This MSDN article explains how to read characters one at a time in a console window. Test each character as it is input with the Char.IsNumber() method, and reject those characters that fail the test.

In a while, I got a solution really short:
double number;
Console.Write("Enter the cost of the item: ");
while (!double.TryParse(Console.ReadLine(), out number))
{
Console.Write("This is not valid input. Please enter an integer value: ");
}
Console.Write("The item cost is: {0}", number);
See you!

Here is one approach. It's probably overkill if you're just starting out in C#, since it uses some more advanced aspects of the language. In any case, I hope you find it interesting.
It has some nice features:
The ReadKeys method takes an arbitrary function for testing whether the string so far is valid. This makes it easy to reuse whenever you want filtered input from the keyboard (e.g. letters or numbers but no punctuation).
It should handle anything you throw at it that can be interpreted as a double, e.g. "-123.4E77".
However, unlike John Woo's answer it doesn't handle backspaces.
Here is the code:
using System;
public static class ConsoleExtensions
{
public static void Main()
{
string entry = ConsoleExtensions.ReadKeys(
s => { StringToDouble(s) /* might throw */; return true; });
double result = StringToDouble(entry);
Console.WriteLine();
Console.WriteLine("Result was {0}", result);
}
public static double StringToDouble(string s)
{
try
{
return double.Parse(s);
}
catch (FormatException)
{
// handle trailing E and +/- signs
return double.Parse(s + '0');
}
// anything else will be thrown as an exception
}
public static string ReadKeys(Predicate<string> check)
{
string valid = string.Empty;
while (true)
{
ConsoleKeyInfo key = Console.ReadKey(true);
if (key.Key == ConsoleKey.Enter)
{
return valid;
}
bool isValid = false;
char keyChar = key.KeyChar;
string candidate = valid + keyChar;
try
{
isValid = check(candidate);
}
catch (Exception)
{
// if this raises any sort of exception then the key wasn't valid
// one of the rare cases when catching Exception is reasonable
// (since we really don't care what type it was)
}
if (isValid)
{
Console.Write(keyChar);
valid = candidate;
}
}
}
}
You also could implement an IsStringOrDouble function that returns false instead of throwing an exception, but I leave that as an exercise.
Another way this could be extended would be for ReadKeys to take two Predicate<string> parameters: one to determine whether the substring represented the start of a valid entry and one the second to say whether it was complete. In that way we could allow keypresses to contribute, but disallow the Enter key until entry was complete. This would be useful for things like password entry where you want to ensure a certain strength, or for "yes"/"no" entry.

This code will allow you to:
Write only one dot (because numbers can have only one decimal separator);
One minus at the begining;
One zero at the begining.
It means that you not be able to write something like: "00000.5" or "0000...-5".
class Program
{
static string backValue = "";
static double value;
static ConsoleKeyInfo inputKey;
static void Main(string[] args)
{
Console.Title = "";
Console.Write("Enter your value: ");
do
{
inputKey = Console.ReadKey(true);
if (char.IsDigit(inputKey.KeyChar))
{
if (inputKey.KeyChar == '0')
{
if (!backValue.StartsWith("0") || backValue.Contains('.'))
Write();
}
else
Write();
}
if (inputKey.KeyChar == '-' && backValue.Length == 0 ||
inputKey.KeyChar == '.' && !backValue.Contains(inputKey.KeyChar) &&
backValue.Length > 0)
Write();
if (inputKey.Key == ConsoleKey.Backspace && backValue.Length > 0)
{
backValue = backValue.Substring(0, backValue.Length - 1);
Console.Write("\b \b");
}
} while (inputKey.Key != ConsoleKey.Enter); //Loop until Enter key not pressed
if (double.TryParse(backValue, out value))
Console.Write("\n{0}^2 = {1}", value, Math.Pow(value, 2));
Console.ReadKey();
}
static void Write()
{
backValue += inputKey.KeyChar;
Console.Write(inputKey.KeyChar);
}
}

You can do it with a single line code as follows:
int n;
Console.WriteLine("Enter a number: ");
while (!int.TryParse(Console.ReadLine(), out n)) Console.WriteLine("Integers only allowed."); // This line will do the trick
Console.WriteLine($"The number is {n}");
You can change int into double in case you wanted to allow double instead of integers and so on.

string input;
double price;
bool result = false;
while ( result == false )
{
Console.Write ("\n Enter the cost of the item : ");
input = Console.ReadLine ();
result = double.TryParse (input, out price);
if ( result == false )
{
Console.Write ("\n Please Enter Numbers Only.");
}
else
{
Console.Write ("\n cost of the item : {0} \n ", price);
break;
}
}

How do I prevent crashing due to invalid input in C#?

The program I've written is set to only accept positive integers as input. If the user inputs a letter instead, then it crashes. Negative integers don't cause any problems, though it's not 'valid' in regards to how my program functions.
What I want to do is:
Prevent the program from crashing from invalid input.
Display an error message if the input is invalid
Have the program continue where it left off, without affecting the rest of the program.
Also, a part of my program involves division. Is there a way to prevent the user from entering all zeros?
This is in C#
My code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace OverallCalculator
{
class Program
{
static void Main(string[] args)
{
bool shouldContinue;
do
{
Console.WriteLine("Enter Striking Level: ");
string striking = Console.ReadLine();
Console.WriteLine("Enter Grappling Level: ");
string grappling = Console.ReadLine();
Console.WriteLine("Enter Submission Level: ");
string submission = Console.ReadLine();
Console.WriteLine("Enter Durability Level: ");
string durability = Console.ReadLine();
Console.WriteLine("Enter Technical Level: ");
string technical = Console.ReadLine();
Console.WriteLine("Enter Speed Level: ");
string speed = Console.ReadLine();
Console.WriteLine("Enter Hardcore Level: ");
string hardcore = Console.ReadLine();
Console.WriteLine("Enter Charisma Level: ");
string charisma = Console.ReadLine();
int gra = Convert.ToInt32(grappling);
int str = Convert.ToInt32(striking);
int dur = Convert.ToInt32(durability);
int spd = Convert.ToInt32(speed);
int tec = Convert.ToInt32(technical);
int hdc = Convert.ToInt32(hardcore);
int cha = Convert.ToInt32(charisma);
int sub = Convert.ToInt32(submission);
int total = str + gra + sub + dur + tec + spd + cha + hdc;
int overall = total / 8 + 8;
Console.WriteLine("The Overall is " + overall);
Console.WriteLine("Do you wish to continue? y/n? ");
if (Console.ReadLine() == "y")
{
shouldContinue = true;
}
else break;
} while (shouldContinue == true);
}
}
}

int value = 0;
if (!int.TryParse(input, out value))
{
MessageBox.Show("Oops");
} else {
// use the value in the variable "value".
}

static void Main(string[] args)
{
bool validInput = false;
string inputString;
UInt32 validPositiveInteger = 0;
while (!validInput)
{
Console.WriteLine("Please enter a positive 32 bit integer:");
inputString = Console.ReadLine();
if (!UInt32.TryParse(inputString, out validPositiveInteger))
{
Console.WriteLine("Input was not a positive integer.");
}
else if (validPositiveInteger.Equals(0))
{
Console.WriteLine("You cannot enter zero.");
}
else
{
validInput = true;
//Or you could just break
//break;
}
}
Console.WriteLine(String.Format("Positive integer = {0}", validPositiveInteger));
}

Here you go:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace OverallCalculator
{
class Program
{
static void Main(string[] args)
{
bool shouldContinue = true;
while (shouldContinue)
{
int strikingLevel = GetValue("Enter Striking Level: ");
int grapplingLevel = GetValue("Enter Grappling Level: ");
int submissionLevel = GetValue("Enter Submission Level: ");
int durabilityLevel = GetValue("Enter Durability Level: ");
int technicalLevel = GetValue("Enter Technical Level: ");
int speedLevel = GetValue("Enter Speed Level: ");
int hardcoreLevel = GetValue("Enter Hardcore Level: ");
int charismaLevel = GetValue("Enter Charisma Level: ");
int total = strikingLevel + grapplingLevel + durabilityLevel + submissionLevel +
technicalLevel + speedLevel + charismaLevel + hardcoreLevel;
int overall = total / 8 + 8;
Console.WriteLine("\nThe Overall is {0}.", overall);
while (true)
{
Console.WriteLine("Do you wish to continue? y/n? ");
string response = Console.ReadLine();
if (response.Equals("y", StringComparison.CurrentCultureIgnoreCase) ||
response.Equals("yes", StringComparison.CurrentCultureIgnoreCase))
{
shouldContinue = true;
break;
}
else if (response.Equals("n", StringComparison.CurrentCultureIgnoreCase) ||
response.Equals("no", StringComparison.CurrentCultureIgnoreCase))
{
shouldContinue = false;
break;
}
}
}
}
private static int GetValue(string prompt)
{
while (true)
{
Console.WriteLine(prompt);
string input = Console.ReadLine();
int value;
if (int.TryParse(input, out value))
{
if (value <= 0)
Console.WriteLine("Please enter a positive number.");
else
return value;
}
else
{
Console.WriteLine("Please enter a number.");
}
}
}
}
}

Yes... before you do anything calculations, you need to validate the data you are going to use. If any data is incorrect, then you display a messagebox detailing the errors and return focus to the form so the user can fix the errors. Repeat as necessary.

I wrote this one many moons ago when I first learned C#. It is a conversion from a VB function that I got back in VB5 days. The major benefit of the function is that there is no error - an input will just not allow any characters outside of the predefined list.
/***********************************************************************
* bool ValiText(char inChar,
* string valid,
* bool editable,
* bool casesensitive
* Description: Validate Input Characters As They Are Input
* Notes: For each control whose input you wish to validate, just put
* e.Handled = ValiText(e.KeyChar, "0123456789/-" [,true][,true])
* In The KeyPress Event
***********************************************************************/
public bool ValiText(char inChar, string valid, bool editable, bool casesensitive)
{
string inVal = inChar.ToString();
string tst = valid;
/// Editable - Add The Backspace Key
if (editable) tst += ((char)8).ToString();
/// Case InSensitive - Make Them Both The Same Case
if (!casesensitive)
{
tst = tst.ToLower();
inVal = inVal.ToLower();
}
return tst.IndexOf(inVal,0,tst.Length) < 0;
}
public bool ValiText(char inChar, string valid, bool editable)
{
string tst = valid;
/// Editable - Add The Backspace Key
if (editable) tst += ((char)8).ToString();
return tst.IndexOf(inChar.ToString(),0,tst.Length) < 0;
}
public bool ValiText(char inChar, string valid)
{
return valid.IndexOf(inChar.ToString(),0,valid.Length) < 0;
}
Note That This Will Not Work On A Web APP.