C#•3y ago

Only numbers

Console.WriteLine("    Please enter a Number");
MyNumber1 = Convert.ToInt32(Console.ReadLine());

Console.WriteLine("    Please enter a Number");
MyNumber1 = Convert.ToInt32(Console.ReadLine());

how to make if player tried to enter a char to decline and ask him to send a number

4 Replies

eult 🇵🇸🇵🇸OP•3y ago

while (beetween != "+" && beetween !=  "-" && beetween !=  "*" && beetween !=  "/")
{
Console.WriteLine("    Please make sure you use");
Console.WriteLine("       + or - or * or /");
beetween = Convert.ToString(Console.ReadLine());
}

while (beetween != "+" && beetween !=  "-" && beetween !=  "*" && beetween !=  "/")
{
Console.WriteLine("    Please make sure you use");
Console.WriteLine("       + or - or * or /");
beetween = Convert.ToString(Console.ReadLine());
}

like this but for a number 🙂

Unknown User•3y ago

Message Not Public

MODiX•3y ago

The TryParse pattern is considered best practice of parsing data from a string: - a TryParse method returns true or false to inform you if it succeeded or not, so you can use it directly in a condition, - since C# 7 you can declare a variable that will be used as an out argument inline in an argument list, - it forces you to check if the out argument contains valid data afterwards, Avoid: Convert.ToInt32 — it's a bad choice for parsing an int. It exists only for backwards compatibility reasons and should be considered last resort.

return Convert.ToInt32(null); //returns 0. null should not be considered as 0 ever
return Convert.ToInt32("asdf"); //throws FormatException

return Convert.ToInt32(null); //returns 0. null should not be considered as 0 ever
return Convert.ToInt32("asdf"); //throws FormatException

(Note: Convert does contain useful conversion methods: To/FromBase64String, To/FromHexString, ToString(X value, int toBase), ToX(string? value, int fromBase)) Avoid: int.Parse — you have to use a try/catch statement to handle invalid input, which is a less clean solution.

var number = int.Parse("abc"); //throws FormatException
var number = int.Parse(""); //throws FormatException

var number = int.Parse("abc"); //throws FormatException
var number = int.Parse(""); //throws FormatException

Use int.TryParse https://docs.microsoft.com/en-us/dotnet/api/system.int32.tryparse?view=net-5.0#System_Int32_TryParse_System_String_System_Int32__

if (int.TryParse(someInput, out var result))
{
  Console.WriteLine($"Thanks for giving me the following number: {result}!");
}
else
{
  Console.WriteLine("You didn't give me a valid number :c");
}

if (int.TryParse(someInput, out var result))
{
  Console.WriteLine($"Thanks for giving me the following number: {result}!");
}
else
{
  Console.WriteLine("You didn't give me a valid number :c");
}

Int32.TryParse Method (System)

Converts the string representation of a number to its 32-bit signed integer equivalent. A return value indicates whether the operation succeeded.

Buddy•3y ago

Also, don't use ReadLine, use ReadKey ReadLine reads an entire line, until ENTER has been pressed (as it is named), while ReadKey only reads a certain key.

Gaming

Programming

Only numbers