C#•3mo ago

✅ Beginner help

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace Exercise_2_Task_1 { internal class Program { static void Main(string[] args) { int testscore = 0; do { Console.WriteLine(); Console.Write("Input test score: "); testscore = Convert.ToInt32(Console.ReadLine());
if (testscore == -1) { Console.Write("Well done, Pres ENTER To Exit...."); Console.ReadLine(); Console.WriteLine(); Environment.Exit(0); } else if (testscore < -1) { Console.WriteLine("Invalid Integer. Please Retry"); } else if (testscore > 100) { Console.WriteLine("Invalid Integer. Please Retry"); }
else if (testscore >= 0 && testscore <= 49) { Console.WriteLine("You need to put in more work!");
} else if (testscore >= 50 && testscore <= 79) { Console.WriteLine("Could you do better? ");
} else if (testscore >= 80 && testscore <= 100) { Console.WriteLine("Well Done!");
}
} while (true);
} } } How can i make it so if they enter like a word 'dog' it says invalid. And Re loops again

22 Replies

Mary Cooper•3mo ago

i mean, if the user enters anything but an interger, it just says invalid, Please Enter a valid integer and then displays the Input test score again

SinFluxx•3mo ago

$tryparse

MODiX•3mo ago

When you don't know if a string is actually a number when handling user input, use int.TryParse (or variants, e.g. double.TryParse)

if(int.TryParse("123", out int number))
{
    var total = number + 1;
    Console.WriteLine(total); // output: 124
}

if(int.TryParse("123", out int number))
{
    var total = number + 1;
    Console.WriteLine(total); // output: 124
}

TryParse returns a bool, where true indicates successful parsing. Remarks: - Avoid int.Parse if you do not know if the value parsed is definitely a number. - Avoid Convert.ToInt32 entirely, this is an older method and Parse should be preferred where you know the string can be parsed. Read more here

Mary Cooper•3mo ago

is there anyway to do it with the else, else if or if loops? i mean without tryparse

Pobiega•3mo ago

When pasting $code, its really helpful if you do it right so we get syntax highlighting and a monospace font.

MODiX•3mo ago

To post C# code type the following: ```cs // code here ``` Get an example by typing $codegif in chat For longer snippets, use: https://paste.mod.gg/

Mary Cooper•3mo ago

i havent learnt that yet okay

maxmahem•3mo ago

Well you can parse it manually but... TryParse will be way easier.

Pobiega•3mo ago

TryParse is 100% the way to go here. Your alternatives are manual parsing (much harder) or try/catch (more complicated)

TheRanger•3mo ago

well you could iterate through each character in the string and check if its a digital number or not

maxmahem•3mo ago

It is interesting to learn the pattern try parses uses though.

Mary Cooper•3mo ago

i know but if they see ive used something we havent covered in class that wont go well for me we have covered try catch

Pobiega•3mo ago

then use try catch

TheRanger•3mo ago

Pobiega•3mo ago

but be aware that its the bad way to do this, in the future

Mary Cooper•3mo ago

yeah im noty sure why he hasnt taught us tryparse

hoggy077•3mo ago

Since you stipulated it should loop, you can also use continue; in future to skip the current loop & move onto the next

Mary Cooper•3mo ago

okay thankyou guys

maxmahem•3mo ago

int result = 0;
foreach (char c in input)
  if (IsDigit(c)) 
    result = result * 10 + (c - '0');

int result = 0;
foreach (char c in input)
  if (IsDigit(c)) 
    result = result * 10 + (c - '0');

this is like the 'standard' int parsing pattern.

Mary Cooper•3mo ago

okay i see thanks

TheRanger•3mo ago

if they taught them int.Parse i dont see why we should use this or Convert.ToInt32

maxmahem•3mo ago

🤷 I don't either, but they asked for a method using loops. this is a method using loops.

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✅ Beginner help