CODEWITHSUNDEEP
c#
Robert
Robert

Reputation: 686

Setting PI decimal places to user given number of places in C#

I'm trying to do a simple operation where I display the value of PI to a user declared decimal length. For instance, if a user enters 2, PI will print out 3.14. However, I keep getting an ArgumentsOutOfBounds error. Can anyone explain to me what I'm doing wrong?

class PiToDecimalPlaces{
    public static void Main(){
        int decimalPlaces = (int)Console.Read();
        Console.WriteLine(Round(decimalPlaces));
    }
    public static double Round(int places){
        double piToPlaces = Math.Round(Math.PI, places);
        return piToPlaces;
    }
}

Upvotes: 0

Views: 316

Answers (3)

Sach
Sach

Reputation: 10393

When you directly read using Console.Read(), you're reading the ASCII value of input into the decimalPlaces.

So if you entered 2, the value of decimalPlaces would be 50.

What you need to do is use Console.ReadLine() and do int.TryParse() on the input, and then pass it to your Round() method.

string strNum = Console.ReadLine();
int decimalPlaces;
int.TryParse(strNum, out decimalPlaces);
Console.WriteLine(Round(decimalPlaces));

Upvotes: 0

Vijayanath Viswanathan
Vijayanath Viswanathan

Reputation: 8541

Please modify the line you are reading value from console to,

int decimalPlaces = Convert.ToInt32(Console.ReadLine());

Upvotes: 0

Vikhram
Vikhram

Reputation: 4394

Couple of things.

First: The below line is logically incorrect. The output returned by Read is a char in the int variable

int decimalPlaces = (int)Console.Read();

What you need is 

int decimalPlaces = int.Parse(Console.ReadLine());

Second: Your function should really use decimal and not double when you want to do fixed point precision since double is a floating point precision value

public static decimal Round(int places){
    decimal piToPlaces = Math.Round((decimal)Math.PI, places);
    return piToPlaces;
}

This should fix your exception and also, avoid any potential Floating Point Precision issue

Upvotes: 2

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