I have declared some values as doubles:

double mean;
double median;

Since the mean after the calculation is a whole number, it is showing without any decimal value. But I need 2 decimal values.
eg:- if the mean is 255, I need to show it as 255.00.
How to achieve this?

What I have tried: Round(mean,2)

Still showing 255

Need 255.00

Need the same for the numbers from the data file too. Need to show the whole number as a decimal number with 2 precision.

CodePudding user response：

try this:

  decimal a = 255;
  var result = Math.Round(a, 2).ToString("0.00");

CodePudding user response：

There are separate 2 issues here:

1. Mathematically rounding a double value to 2 decimal places. This will keep 255, and 255.01 as is, but convert e.g. 123.123 to 123.12.
2. Format a string with 2 fixed decimal places. This will add e.g. ".00" if the value is an integer.

Both are demonstrated below:

using System;

namespace ConsoleApp1
{
    internal class Program
    {

        static void test(double d)
        {
            // Mathematically round to 2 decimal places
            double d2 = Math.Round(d, 2);
            // Use d2 if you need a double value with 2 decimal places.

            // Format string with 2 fixed decimal places:
            string str = d.ToString("0.00");

            // Write the formatted string:
            Console.WriteLine(str);
        }

        static void Main(string[] args)
        {
            test(255);
            test(255.01);
            test(123.123);
        }
    }
}

Output:

255.00
255.01
123.12