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Trying to get the user to input numbers and when the user hits end the program will stop in a while loop and give the sum of numbers

I'm trying to get a while loop in my C# program to get the user to enter a number. When their finish they'll input end and the while loop will stop and add up all the numbers the user has entered. I don't know where to store the text End in my while loop
List <int> nums = new List <int>();
int sum = nums.Sum();
string enteredText = "";
while (true)
{
Console.Write("Enter a number or the word End to finish : ");
int number = Convert.ToInt32(Console.ReadLine());
// nums.Add(int.Parse(Console.ReadLine()));
if (enteredText.Equals("End"))
{
break;
}
}
// Console.WriteLine("The sum is: " + sum);
// Console.WriteLine($"Sum = {nums.Sum()}");

First thing if the entred string contains characters Convert.ToInt32 Method gives error because this string cannot be converted to integer.
but you can using the int.TryParse Method to convert a string representation of number to an integer, if the string cannot be converted, then the int.TryParse Method returns false ,and if conversion succeeded, the method will return true.
The solution:
List <int> nums = new List <int>();
int number = 0;
string enteredText = string.Empty;
while (true) {
Console.Write("Enter a number or the word End to finish : ");
enteredText = Console.ReadLine();
//check if enteredText is int type
if (int.TryParse(enteredText, out number)) {
nums.Add(number);
}
else if (enteredText.Equals("End")) {
break;
}
}
Console.WriteLine($"Sum = {nums.Sum()}");
Console.ReadKey();

How to loop a Console.ReadLine to the infinite?

Hello i'm trying to create a calculator game but it loops only 2 times and (idk why)not til the user finds the result with input. And i'll later see how to make a random generator of numbers instead of writing them by myself in the code. Ty for helping.
Yassine
using System;
namespace G
{
class Program
{
static void Main(string[] args)
{
Calcul(2, 2);
}
static void Calcul(int nombre1, int nombre2)
{
int result = nombre1 + nombre2;
Console.WriteLine("Combien font " + nombre1 + " + " + nombre2);
int supposed = int.Parse(Console.ReadLine());
if(result != supposed)
{
Console.WriteLine("Try again!");
supposed = int.Parse(Console.ReadLine());
}
else
{
Console.Clear();
Console.WriteLine("Correct!");
}
}
}
}

You can change your if statement to a while loop whose condition is that the input does not match the result. We can also use int.TryParse with Console.ReadLine to handle cases where the user doesn't enter a valid number. This works by taking an out parameter that gets set to the parsed value if it's successful, and it returns a bool that indicates success. Perfect for a loop condition!
Then you can put the "success" message after the body of the while loop (because the only way to exit the loop is to get the correct answer). It would look something like:
static void Calcul(int nombre1, int nombre2)
{
int result = nombre1 + nombre2;
int input;
Console.Write($"Combien font {nombre1} + {nombre2} = ");
while (!int.TryParse(Console.ReadLine(), out input) || input != result)
{
Console.WriteLine("Incorrect, please try again.");
Console.Write($"Combien font {nombre1} + {nombre2} = ");
}
Console.WriteLine("Correct! Press any key to exit.");
Console.ReadKey();
}

system.formatexception in while(true) loop

The subject is a little problem:
Write a program and continuously ask the user to enter a number or "ok" to exit. Calculate the sum of all the previously entered numbers and display it on the console.
Here is my code:
var sum = 0;
while (true)
{
Console.WriteLine("Enter a number or ok to exit:");
if (Console.ReadLine() == "ok") break;
sum += Convert.ToInt32(Console.ReadLine());
Console.WriteLine(sum);
}
When I tap ok, it terminate.
When I tap number and enter, it shows system.formatexception:The input string is not in the correct format.
I know one of the solution is
var sum = 0;
while (true)
{
Console.Write("Enter a number (or 'ok' to exit): ");
var input = Console.ReadLine();
if (input.ToLower() == "ok")
break;
sum += Convert.ToInt32(input);
}
Console.WriteLine("Sum of all numbers is: " + sum);
Maybe My code looks a little weired, But Why is my code wrong?

Reason is input will be "ok". Can not convert that into an integer.
first you have to store the first input value into other variable.
then convert that string into integer and get summation.
var sum = 0;
while (true)
{
Console.Write("Enter a number (or 'ok' to exit): ");
var input = Console.ReadLine();
int newVariable = 0;
if (input.ToLower() != "ok")
{
newVariable = Convert.ToInt32(input);
}
input = Console.ReadLine();
if (input.ToLower() == "ok"){
break;
sum += newVariable;
}
}
Console.WriteLine("Sum of all numbers is: " + sum);
If there any problem here please let me know.

Try this:
var sum = 0;
while (true)
{
Console.WriteLine("Enter a number or ok to exit:");
String ans = Console.ReadLine();
if (ans == "ok" || ans.ToLower() == "ok") break;
sum += Convert.ToInt32(ans);
Console.WriteLine(sum);
}
Here I've just store input entered by user in one variable and use that variable in further process.
In your first code you have take input two times, first one is in IF condition and second in parsing, that may cause the problem.

The correct way to do this is to use int.TryParse for your conversion from a string to a number. TryParse attempts to convert the string to a number, but if it cannot do so (for example, the string contains more than just numeric digits) it will fail gracefully instead of causing an exception. The other answers so far will all cause an unhandled FormatException if something non-numeric is entered other than "ok". By using int.TryParse you can handle the case where it's a valid number, as well as the case where it is invalid, and then alert the user. Here's an example within the context of your code:
// I prefer using concrete types for numbers like this, so if anyone else
// reads it they know the exact type and numeric limits of that type.
int sum = 0;
int enteredNumber = 0;
while (true)
{
Console.Write("Enter a number (or 'ok' to exit): ");
var consoleInput = Console.ReadLine();
if (consoleInput.ToLower() == "ok")
break;
if(int.TryParse(consoleInput, out enteredNumber))
{
sum += enteredNumber;
}
else
{
Console.WriteLine("You entered '" + consoleInput + "', which is not a number.");
}
}
Console.WriteLine("Sum of all numbers is: " + sum.ToString());
This is better because you know you have no control over the user's input other than to validate it yourself, and so it's better to speculatively convert the number and be alerted to success or failure without triggering an exception. Wrapping everything with a try/catch block is not a proper solution.

Your first code example, as rightly pointed out in the comments, reads a line, tests it for 'ok', then throws it away, reads another line, and uses that to add to the sum, which is not what you wanted.
After some quick research, I would say the most concise way to handle this in C# is probably something like your second code example. In F# I was able to come up with the following examples (one is a loop, the other uses sequences, i.e. IEnumerable<_>s) but I found no concise way to get the same with C# and LINQ…
let inputLoop () =
let rec aux sum =
match stdin.ReadLine () with
| "ok" -> sum
| s -> aux (sum + int s)
stdout.WriteLine (aux 0 |> string)
let inputSeq () =
fun _ -> stdin.ReadLine ()
|> Seq.initInfinite
|> Seq.takeWhile (fun s -> s <> "ok")
|> Seq.sumBy int
|> string
|> stdout.WriteLine

Try it :)
var sum = 0;
while (true)
{
Console.Write("Enter a number: or ok to exit : ");
String input = Console.ReadLine();
if (input == "ok" || input.ToLower() == "ok") break;
if(string.IsNullOrWhiteSpace(input))
continue;
sum += Convert.ToInt32(input);
}
Console.WriteLine("Total Result: " + sum);
Write a program and continuously ask the user to enter a number or "ok" to exit. Calculate the sum of all the previously entered numbers and display it on the console. Happy Coding

var sum = 0;
while (true)
{
Console.Write("Write number or write \"ok\" for exit: ");
var input = Console.ReadLine();
if (input.ToLower() != "ok")
{
sum += Convert.ToInt32(input);
continue;
}
break;
}
Console.WriteLine("All sum: " + sum + ".");

This is one way to do it. I'm just learning to do this!
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Enter number to know the sum or press ok to exit and display the sum");
int sum = 0;
while (true) // to run the program continously asking user input
{
Console.WriteLine("Enter Number: ");
var input = Console.ReadLine(); // takes user input
if (input.ToLower() == "ok") // compares user input to string ok
break; //if user input is ok, breaks the loop and sum is displayed
var inputInInt = Convert.ToInt32(input); // if user input is int, continues to convert it to integer
sum += inputInInt; // user input in interger is added to sum
}
Console.WriteLine("The sum of entered numbers is: " + sum);
Console.ReadLine();
}
}

c# Need help trying to put in and run two loops for the same input

I've put in a loop with Try.Parse so that if the user enters a decimal number, the program will ask them to enter another number until they put in a integer and then the program will carry on with the next part.
However what i'm struggling with is putting in another loop that makes it so that the user can only enter a number between 1 and 100, and if they don't there should be an error message that loops until they do enter this. Id like them to run at the same time and i have this one, but i want it to also check whether its in the range and i'm not sure how to do that.
I'm new to programming so I'm not great at this.
Thank you in advance!
string inputcost;
string inputmoney;
int validcost;
int validmoney;
int changereq;
Console.Write("Please Enter The Cost, In Pennies, Of The Item You Have Purchased: ");
inputcost = Console.ReadLine();
bool result = int.TryParse(inputcost, out validcost);
while (!int.TryParse(inputcost, out validcost))
{
if (result == true)
{
Console.Write("Valid Value");
}
if (result == false)
{
Console.Write("Please Enter A Valid Integer Value");
Console.WriteLine();
inputcost = Console.ReadLine();
}
}

Your problem here is that the result variable you're looking at is only written once: outside the loop. Consider trying something like the following pseudocode (a do-while loop works exactly the same as a while loop, except it always gets executed once before the condition is checked):
bool validInput;
do
{
// If you set it true to begin with, you can set it false on any unmet conditions
// If it doesn't get set false, you've got a valid input and can exit the loop.
validInput = true;
Read input from user
Check if it's a valid integer, if not print message and validInput = false
Check if it's between 1-100, if not print message and validInput = false;
} while (!validInput);
Then if you want to tackle something more advanced, look at the continue keyword.

Try something like this.
string inputcost;
string inputmoney;
int validcost;
int validmoney;
int changereq;
while (true)
{
Console.Write("Please Enter The Cost, In Pennies, Of The Item You Have Purchased: ");
inputcost = Console.ReadLine();
if (!(valuecost >=1 && valuecost <=100))
{
Console.Write("Please enter value between 1 and 100.");
}
bool result = int.TryParse(inputcost, out validcost);
if (result == true)
{
Console.Write("Valid Value");
}
if (result == false)
{
Console.Write("Please Enter A Valid Integer Value");
}
}

It would be useful to use a method and do something like:
Console.Write("Please Enter The Cost, In Pennies, Of The Item You Have Purchased: ");
inputcost = Console.ReadLine();
bool result = false;
while (!result)
{
result = checkNumber();
}
public static bool checkNumber()
{
if(inputcost < 1 || inputcost > 100)
{
Console.Write("Please Enter a valid value: ");
inputcost = Console.ReadLine();
return false;
}
else
return true;
}

Hope this helps.
string inputcost;
string inputmoney;
int validcost = 0;
int validmoney = 0;
Console.Write("Please Enter The Cost, In Pennies, Of The Item You Have Purchased: ");
inputcost = Console.ReadLine();
// only accept integers
while (!int.TryParse(inputcost, out validcost))
{
Console.Write("Please Enter An Integer Value: ");
inputcost = Console.ReadLine();
}
// valid integer input in variable validcost
bool done = false;
while (!done)
{
Console.Write("Enter an integer between 1 and 100: ");
inputmoney = Console.ReadLine();
if (int.TryParse(inputmoney, out validmoney))
{
if (validmoney > 0 && validmoney < 101)
{
done = true;
}
else
{
Console.WriteLine("Invalid input: " + inputmoney);
}
}
else
{
Console.WriteLine("Invalid input: " + inputmoney);
}
}
//validcost is an integer and validmoney is an integer between 1 and 100
Console.WriteLine("validcost: " + validcost + " validmoney: " + validmoney);
Console.ReadKey();

Validate if integer equals string

So im trying to simply check if my variable is entered as a string, I want the if statement to go through and not an unhandled exception...
Here's my code:
Console.Write("Input: ");
int i;
bool success = int.TryParse("", out i);
if (success) {
Console.WriteLine("Enter Integer!");
} else {
i = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Output: ", i);
}
So what am I doing wrong here? Every time I am entering a string, I'm not getting to the if statement, only a crash!

The problem in your code is that the value passed to TryParse has no connection to the value passed to Convert.ToInt32. You should read the value in, then call TryParse with the same value:
Console.WriteLine("Enter an integer:");
var s = Console.ReadLine();
int i;
if (int.TryParse(s, out i)) {
Console.WriteLine("You entered an integer");
} else {
Console.WriteLine("You did not enter an integer");
}
If you would like to continue reading until the end-user enters a valid int, add a loop, like this:
int i;
do {
Console.WriteLine("Enter an integer:");
var s = Console.ReadLine();
} while (!int.TryParse(s, out i));

I think you should do it this way
Console.Write("Input: ");
int i;
bool success = int.TryParse(Console.ReadLine(), out i); //Getting the input and checking it
if (!success)
{
Console.WriteLine("Enter Integer!");
}
else
{
Console.WriteLine("Output: ", i);
}
In your code you were getting the value in the else statement and if your input cannot be parsed to int, then exception throws.