✅ trying to validate an input

i have this skeleton program for a game that doesnt seem to validate inputs correctly. i dont really know how to correct it [images below]

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

(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

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");
}

i've tried doing that

i did tryparse but i dont think im doing it right

hold on

ill show u another example thats probably simpler that also isnt working

i think you've helped me on this before with a previous example

@Retax this is something that i did before using tryparse that seemed to work

it was a similar situation i had to validate an input and make sure it was an integer even if the user entered something weird

im just not 100% on how to use tryparse in the context of a dowhile loop

i have SquareIsValid as a bool var

so i need another one to check the input?

right

what's going in and out

i already have an int choice

i was thinking about another choice variable

as a string

that i can just put as

i did it on another project

wait

yea

and then i had

i wanted to replicate something like this

@Retax little experimenting

me too

im trying to validate an input

my problem is

if a user enters a string

thats not between 1-3 or 9

it just crashes

which part

the whole thing?

i read the documentation i still dont fully understand how tryparse actually works

it literally just converts a string to an integer and gets stored in a boolean?

this is so utterly confusing bro

i really appreciate your patience lol

okay done that was an easy switch

only problem is

what do i do with Choice

yeah thats the problem i got given this skeleton program and got told to alter it

so if i change Choice

everything else fails

aha

okay

done

it works

thank you my friend i appreciate it

its a really weird project that ive been given

idk what any of the words mean

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