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How do I set a value in one method and then return that value to another method?

I need some help. If I understand this right, the value of "int F" gets sent to "FtoC" converted and then returned to the MenuSelect1 method.
Now I want to return or save the value "int C" has after its been converted to the MenuSelect2 method? I have tried everything I can think of, but I just get errors. (I have reset the code to original state now where MenuSelect1 and 2 är void). Whats an easy way to solve this? Thank you.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
public static class SecondClass {
public static int FtoC(int fahrenheit)
{
int C = ((fahrenheit - 32) * 5) / 9;
return C;
}
public static void MenuSelect1()
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
int C = SecondClass.FtoC(F);
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
break;
}
}
Console.ReadKey();
}
public static void MenuSelect2()
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write("Temperature: {0}");
Console.ReadKey();
}
}

You could also save the value of C as a property / field in your class. Here is an example of saving it as a field called _celcius:
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
public static class SecondClass {
private static int _celcius = 0; // <--- Your field
public static int FtoC(int fahrenheit)
{
int C = ((fahrenheit - 32) * 5) / 9;
return C;
}
public static void MenuSelect1()
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
_celcius = SecondClass.FtoC(F); // <--- Assign field here
if (_celcius < 80 || _celcius > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(_celcius + "°C is perfect. Start the sauna and enjoy!");
break;
}
}
Console.ReadKey();
}
public static void MenuSelect2()
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write("Temperature: {0}", _celcius); // <--- Use your field here
Console.ReadKey();
}
}```

You either call the MenuSelect2() directly from the MenuSelect1()
public static void MenuSelect1()
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
int C = SecondClass.FtoC(F);
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
// here
MenuSelect2(C);
break;
}
}
Console.ReadKey();
}
public static void MenuSelect2(int C)
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write($"Temperature: {C}"); // <- notice the $ for interpolated strings.
}
Or return the value from the MainSelect1() to the caller which calls the MainSelect2() method.
public static void Main()
{
// get the temperature
int C = MenuSelect1();
// pass it to the other method.
MenuSelect2(C);
Console.ReadKey();
}
public static int MenuSelect1() // <- change the signature (return int)
{
while (true)
{
int F = 0;
Console.Write("\nType how many degrees Fahrenheit you want: ");
try
{
F = Convert.ToInt32(Console.ReadLine());
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.DarkRed;
Console.WriteLine("ERROR!");
Console.ForegroundColor = ConsoleColor.White;
}
int C = SecondClass.FtoC(F);
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
return C; // return the value to the caller.
}
}
}
public static void MenuSelect2(int C)
{
Console.WriteLine("Starting Sauna. Wait for it to reach desired temperature...");
Console.Write($"Temperature: {C}"); // <- notice the $ for interpolated strings.
}
I rather use the second suggestion, because this way the MenuSelect1() isn't tightcoupled to MenuSelect2() and can be reused for other purposes.

The problem at this point is that the variable C is instantiated and stored inside the method MenuSelect1(), what you should do is create a class variable like int fahrenheitValue and then inside the menuSelect1 method use this.fahrenheitValue = C so the value is stored inside the class variable and then you can access it from everywhere

All the variables that are defined in MenuSelect1() will NOT be visible as soon as the method ends.
You can define a static property in your "SecondClass"
private static int degreesCelsius;
Then you can set this property in
if (C < 80 || C > 87)
{
Console.WriteLine("Try a different temperature.");
}
else
{
Console.WriteLine(C + "°C is perfect. Start the sauna and enjoy!");
degreesCelsius = C;
break;
}
In your MenuSelect2() method you can use it.
Console.Write("Temperature: {0}", degreesCelsius);

Made a guessing game, but I think my code is weirdly put

The code works perfectly, but I am not sure if this is good practice or not. I think it could be improved and made easier, but I don't know how. Maybe I could have used more variables to make it simpler. Or is it fine as long as it works? I also need to work on tidying my code up.
using System;
namespace Lesson_number_16_Building_a_guessing_game
{
class Program
{
static void Main(string[] args)
{
string secretWord = "monkey";
string guess = "";
int count = 3;
Console.WriteLine("Please type an animal name that starts with the letter M, you have 3 guesses: ");
guess = Console.ReadLine();
if (guess == secretWord)
{
Console.WriteLine("Nice, you got it right.");
} else if (guess != secretWord)
{
while (guess != secretWord && count > 1)
{
count--;
Console.WriteLine("Nope, try again! you have " + count + " guesses left");
guess = Console.ReadLine();
if (guess == secretWord)
{
Console.WriteLine("Nice, you got it right.");
} else if (count == 1)
{
Console.WriteLine("You have failed to guess it. It was " + secretWord);
break;
}
}
}
}
}
}

1.Instead of initializing the string guess="", you can always prefer string guess=string.Empty.
2.Try to align the curly braces using keys like Ctrl + K.(It depends on Visual Studio version).

Here's a couple of things I would change:
Get rid of the magic number '1' breaking out of the loop. Declare it
as a const with a meaningful name.
since you're breaking out of the while loop within the while loop when validating the retrycount, there is no point to put the
condition in the while loop as well.
Combine the initial question within the loop as well and break out of the loop when correct.
Combine counter substraction and lowerbound check in one call.
Use the equals method for string comparison with the right culture.
using System;
namespace Lesson_number_16_Building_a_guessing_game
{
internal class Program
{
private static void Main(string[] args)
{
const string secretWord = "monkey";
int count = 3;
const int lowerGuessBound = 0;
Console.WriteLine("Please type an animal name that starts with the letter M, you have 3 guesses: ");
while (true)
{
if (Console.ReadLine().Equals(secretWord, StringComparison.CurrentCulture))
{
Console.WriteLine("Nice, you got it right.");
break;
}
else if (--count == lowerGuessBound)
{
Console.WriteLine($"You have failed to guess it. It was {secretWord}");
break;
}
Console.WriteLine($"Nope, try again! you have {count} guesses left");
}
}
}
}

I think that you can shorten and tidy-up your code to something like:
const string secretWord = "monkey";
string guess = "";
const int count = 3;
Console.WriteLine($"Please type an animal name that starts with the letter M, you have {count} guesses: ");
while(count>0)
{
guess = Console.ReadLine();
count--;
if(guess != secretWord )
{
Console.WriteLine($"Nope, try again! you have {count} guesses left");
}
else
{
count=0;
}
}
if(guess != secretWord )
{
Console.WriteLine($"You have failed to guess it. It was {secretWord}");
}
else
{
Console.WriteLine("Nice, you got it right.");}
}
Using const declaration helps to protect against a code error that changes a value that shouldn't. It can also be used on variable input for functions/methods.
I try not to use == where possible as its easy to type = by mistake.
The string interpolation character $ makes for easier understanding of strings that include parameter values when reading code.

Simple validation

Hey guys looking for a simple validation code for my C# Console Program
Currently have:
public Class1()
{
Console.WriteLine("Enter a, b, c or d:");
string input = Console.ReadLine();
while ((input != "a") && "b" && "c" && "d"))
{
if (input == "a" && "b" && "c" && "d")
{
Console.WriteLine("Success");
}
if (input != "a" && "b" && "c" && "d")
{
Console.WriteLine("Try again");
Console.WriteLine("Enter a, b, c or d:");
string input = Console.ReadLine();
}
}
}
Any help is appreciated! Cheers.

This is a nonsense :
while ((input != "a") && "b" && "c" && "d"))
It can be written that way :
while (aCondition && anotherCondition && yetAnotherCondition && theLastCondition))
(input != "a") is a condition, there's no problem with that, but "b" isn't a condition, it will be considered as true since it's not false or null. I think you would have write : while ((input != "a") && (input != "b") && (input != "c") && (input != "d")))
The same way that condition if (input == "a" && "b" && "c" && "d") should have be written if (input == "a" && input == "b" && input == "c" && input == "d") will provide an algo issue. input can't be at the same time equal to "a", equal to "b", equal to "c" and equal to "d".
Plus, your code won't compile since it's in a class without being wrapped into a method.
Did you read the errors message when trying to run it?

I think the simplest approach would be to create an array of chars that are allowed and validate the input against that:
char[] allowedChars = new char[] { 'a', 'b'};
while(true){
char inputChar = 'z';
if (allowedChars.Length > 1)
{
Console.WriteLine(string.Format("Enter {0} or {1}:", string.Join(", ", allowedChars.Take(allowedChars.Length - 1)), allowedChars[allowedChars.Length - 1]));
}
else
{
Console.WriteLine(string.Format("Enter {0}", allowedChars[0]));
}
var result = char.TryParse(Console.ReadLine(), out inputChar);
if (result && allowedChars.Contains(inputChar))
{
break;
}
Console.WriteLine("Try again");
}
Console.WriteLine("Success");
Console.ReadLine();
When it's a success it'll automatically break out from the while loop and print the Success message.

Firstly, your code cannot just be in a class. It needs to be in a function. Generally you'll see that looking like this
Console.WriteLine("Enter a, b, c or d:");
while ((input != "a") &&(input != "b") && (input != "c") &&(input != "d"))
{
Console.WriteLine("Try again");
string input = Console.ReadLine();
}
Console.WriteLine("Success!");

There is a lot of mistakes in your code, look at mine and try to understand it. It's pretty easy.
Console.WriteLine("Enter a, b, c or d:\r\n");
string input = Console.ReadLine();
while (input != "")
{
if (input == "a" || input == "b" || input == "c" || input == "d")
{
Console.WriteLine("Success\r\n");
}
else
{
Console.WriteLine("Fail\r\n");
}
Console.WriteLine("Enter a, b, c or d:");
input = Console.ReadLine();
}

public Class1()
{
private static List<string> allowedChars= new List<string>(){
"a","b","c","d"
};
public void Verify()
{
Console.WriteLine("Enter a, b, c or d:");
string input = Console.ReadLine();
while (!allowedChars.Contains(input))
{
Console.WriteLine("Try again");
Console.WriteLine("Enter a, b, c or d:");
input = Console.ReadLine();
}
}
}

Why do you use a while loop? It seems quite unneccessary. I do not understand your code as to what the right answer would be, but a simple switch statement should serve your purpose better
Console.WriteLine("Enter a, b, c or d:");
string input = Console.ReadLine();
switch (input)
{
case "a": Console.WriteLine("Success");
break;
case "b":
Console.WriteLine("Try again");
break;
case "c":
Console.WriteLine("Try again");
break;
case "d":
Console.WriteLine("Try again");
break;
default: Console.WriteLine("Enter a, b, c or d:");
break;
}
Console.ReadLine();

I suggest the following code:
// char: we actually input a single character, not string
char input = '\0'; // initialize to make compiler happy
// keep on asking until success
while (true) {
Console.WriteLine("Enter a, b, c or d:");
// ReadKey: We want a single character, not a string
input = Console.ReadKey();
// input is valid if it's in ['a'..'d'] range
if (input >= 'a' && input <= 'd') {
Console.WriteLine("Success");
break;
}
Console.WriteLine("Try again");
}
Edit: in generalized case (see Adriani6's comment below) the code be a little bit more complex. I guess the underlying problem being a kind of questionary, like
Compute 2 x 2 = ?
a. 3
b. 4
c. 5
d. 0
Enter a, b, c or d:
that's why I expect the valid input should ever be in some range ('a'..'d' in the example above) which I preserved.
char from = 'a';
char upto = 'd';
// char: we actually input a single character, not string
char input = '\0'; // initialize to make compiler happy
// Building a title is, probably, the only complex thing (Linq)
string title =
$"Enter {string.Join(", ", Enumerable.Range(from, upto - from).Select(c => (char) c))} or {upto}:";
// keep on asking until success
while (true) {
Console.WriteLine(title);
// ReadKey: We want a single character, not a string
input = Console.ReadKey();
// Uncomment if we want a quit without choice, say, on Escape
//if (input == 27) { // or (input == 'q') if we want to quit on q
// input = '\0';
//
// break;
//}
// input is valid if it's in [from..upto] range
if (input >= from && input <= upto) {
Console.WriteLine("Success");
break;
}
Console.WriteLine("Try again");
}

For starters, I would break out the validation code input into a separate method as you're potentially going to have to call it multiple times if the input validation fails. The same applies for retrieving the input.
As for the validation itself, a simple check that the input string matches "a" OR "b" OR "c" OR "d" will work. You can set up the method to return the boolean value that the expression evaluates to, as below.
Finally, it's just a case of calling ValidateInput until it returns true using a While loop and negating the returned value using the logical negation operator !. Negating the returned value effectively reverses the result of the ValidateInput method. In English this would read as While ValidateInput is NOT True
class Program
{
static void Main(string[] args)
{
while (!ValidateInput(GetInput()))
{
Console.WriteLine("Try again");
}
Console.WriteLine("Success");
Console.Read();
}
private static string GetInput()
{
Console.WriteLine("Enter a, b, c or d:");
return Console.ReadLine();
}
private static bool ValidateInput(string input)
{
return (input == "a" || input == "b" || input == "c" || input == "d");
}
}

Loop for char not working

So, I am attempting to make a loop where if someone enters a char it will execute. If it is wrong it will will display not an option. If I put an Else {Console.WriteLine("Not an option") at the end of the the "end" after my Array() method, it doesn't work either.
So, I am not completely sure of what I am doing. Does this even require a loop? As I would imagine it does to work? Any suggestions would be wonderful.
class Program
{
static void Main(string[] args)
{
string _a = "";
constructor dick = new constructor();
Console.WriteLine("Enter C for constructor, M for method, A for an array...");
Console.WriteLine("Please reference source code to have full details and understanding...");
while (_a.ToUpper() == "C" || "M" || "A")
{
_a = Console.ReadLine();
if (_a.ToUpper() == "C")
{
Console.WriteLine(dick.a);
}
if (_a.ToUpper() == "M")
{
Shit();
}
if (_a.ToUpper() == "A")
{
Array();
}
}
}
public class constructor
{
public string a = "This is a constructor!";
}
static public void Shit()
{
string b = "This is a method!";
Console.WriteLine(b);
}
static public void Array()
{
Console.WriteLine("\nHow large of an array?\n");
string sSize = Console.ReadLine();
int arraySize = Convert.ToInt32(sSize);
int[] size = new int[arraySize];
Random rd = new Random();
Console.WriteLine();
for (int i = 0; i < arraySize; i++)
{
size[i] = rd.Next(arraySize);
Console.WriteLine(size[i].ToString());
}
}
}
}

instead of this:
while (_a.ToUpper() == "C" || "M" || "A")
Define a bool variable and:
bool control = true;
while (control)
{
_a = Console.ReadKey();
var character = _a.KeyChar.ToString().ToUpper();
switch (character)
{
case "C":
Console.WriteLine(dick.a);
control = false;
break;
case "M":
control = false;
Shit();
break;
case "A":
control = false;
Array();
break;
default:
Console.WriteLine("You entered wrong character");
break;
}
}
If you want to force user to enter a correct character, yes you need a loop.And use Console.ReadKey instead of Console.ReadLine if the input is just one character

How can I validate console input as integers?

I have written my codes and i want to validate it in such a way thet it will only allow intergers to be inputed and not alphabets. Here is the code, please I will love you to help me. Thanks.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace minimum
{
class Program
{
static void Main(string[] args)
{
int a = Convert.ToInt32(Console.ReadLine());
int b = Convert.ToInt32(Console.ReadLine());
int c = Convert.ToInt32(Console.ReadLine());
if (a < b)
{
if (a < c)
{
Console.WriteLine(a + "is the minimum number");
}
}
if (b < a)
{
if (b < c)
{
Console.WriteLine(b + "is the minimum number");
}
}
if (c < a)
{
if (c < b)
{
Console.WriteLine(c + "is the minimum number");
}
}
Console.ReadLine();
}
}
}

You should test if it's an int instead of converting in right away.
Try something like :
string line = Console.ReadLine();
int value;
if (int.TryParse(line, out value))
{
// this is an int
// do you minimum number check here
}
else
{
// this is not an int
}

Simply call Readline() and loop with Int.TryParse until the user inputs a valid number :)
int X;
String Result = Console.ReadLine();
while(!Int32.TryParse(Result, out X))
{
Console.WriteLine("Not a valid number, try again.");
Result = Console.ReadLine();
}
Hope that helps

To get the console to filter out alphabetical keystrokes you have to take over input parsing. The Console.ReadKey() method is fundamental to this, it lets you sniff the pressed key. Here's a sample implementation:
static string ReadNumber() {
var buf = new StringBuilder();
for (; ; ) {
var key = Console.ReadKey(true);
if (key.Key == ConsoleKey.Enter && buf.Length > 0) {
return buf.ToString() ;
}
else if (key.Key == ConsoleKey.Backspace && buf.Length > 0) {
buf.Remove(buf.Length-1, 1);
Console.Write("\b \b");
}
else if ("0123456789.-".Contains(key.KeyChar)) {
buf.Append(key.KeyChar);
Console.Write(key.KeyChar);
}
else {
Console.Beep();
}
}
}
You could add, say, Decimal.TryParse() in the if() statement that detects the Enter key to verify that the entered string is still a valid number. That way you can reject input like "1-2".

Do not Convert the input from the user immediately. Put it in a string and use Int32.TryParse(...) to find out whether or not a number was entered. Like this:
int i;
string input = Console.ReadLine();
if(Int32.TryParse(input, out i))
{
// it is a number and it is stored in i
}
else
{
// it is not a number
}

Note that
if (a < b) {
if (a < c) {
is equivalent to
if (a < b && a < c) {
and that this latter form introduces less nesting and is more readable, particularly if your code grows more complex. Also, you should probably never use Convert.ToInt32 - it has a particularly ill-conceived and surprising corner case; and it's also less type-safe than int.Parse which is the superior choice where possible - or int.TryParse when you're unsure whether the string is valid. Basically, avoid Convert.... wherever possible.

string Temp;
int tempInt,a;
bool result=false;
while ( result == false )
{
Console.Write ("\n Enter A Number : ");
Temp = Console.ReadLine ();
result = int.TryParse (Temp, out tempInt);
if ( result == false )
{
Console.Write ("\n Please Enter Numbers Only.");
}
else
{
a=tempInt;
break;
}
}

My preferred solution would be:
static void Main()
{
Console.WriteLine(
(
from line in Generate(()=>Console.ReadLine()).Take(3)
let val = ParseAsInt(line)
where val.HasValue
select val.Value
).Min()
);
}
static IEnumerable<T> Generate<T>(Func<T> generator) {
while(true) yield return generator();
}
static int? ParseAsInt(string str) {
int retval;
return int.TryParse(str,out retval) ? retval : default(int?);
}
Of course, depending on the specification (should invalid number be retried?), it may need to be tweaked.

Double/Float:
I'm just extending #Hans Passant answer (Taking care of DecimalSeparator and "-"):
static double ReadNumber()
{
var buf = new StringBuilder();
for (; ; )
{
var key = Console.ReadKey(true);
if (key.Key == ConsoleKey.Enter && buf.Length > 0)
{
Console.WriteLine();
return Convert.ToDouble(buf.ToString());
}
else if (key.Key == ConsoleKey.Backspace && buf.Length > 0)
{
buf.Remove(buf.Length - 1, 1);
Console.Write("\b \b");
}
else if (System.Globalization.NumberFormatInfo.CurrentInfo.NumberDecimalSeparator.Contains(key.KeyChar) && buf.ToString().IndexOf(System.Globalization.NumberFormatInfo.CurrentInfo.NumberDecimalSeparator) == -1)
{
buf.Append(key.KeyChar);
Console.Write(key.KeyChar);
}
else if ("-".Contains(key.KeyChar) && buf.ToString().IndexOf("-") == -1 && buf.ToString() == "")
{
buf.Append(key.KeyChar);
Console.Write(key.KeyChar);
}
else if ("0123456789".Contains(key.KeyChar))
{
buf.Append(key.KeyChar);
Console.Write(key.KeyChar);
}
else
{
Console.Beep();
}
}
}

var getInput=Console.ReadLine();
int option;
//validating input
while(!int.TryParse(getInput, out option))
{
Console.WriteLine("Incorrect input type. Please try again");
getInput=Console.ReadLine();
}

Try This Simple
try
{
string x= "aaa";
Convert.ToInt16(x);
//if success is integer not go to catch
}
catch
{
//if not integer
return;
}