Truncate number of digit of double value in C#

Question

How can i truncate the leading digit of double value in C#,I have tried Math.Round(doublevalue,2) but not giving the require result. and i didn\'t find any other method in M

Answer 1

I'm sure there's something more .netty out there but why not just:-

double truncVal = Math.Truncate(val * 100) / 100;
double remainder = val-truncVal;

Answer 2

double original = 12.123456789;  

double truncated = Truncate(original, 2);  

Console.WriteLine(truncated.ToString());
// or 
// Console.WriteLine(truncated.ToString("0.00"));
// or 
// Console.WriteLine(Truncate(original, 2).ToString("0.00"));


public static double Truncate(double value, int precision)
{
    return Math.Truncate(value * Math.Pow(10, precision)) / Math.Pow(10, precision);
}

Answer 3

If you are looking to have two points after the decimal without rounding the number, the following should work

string doubleString = doublevalue.ToString("0.0000"); //To ensure we have a sufficiently lengthed string to avoid index issues
Console.Writeline(doubleString
             .Substring(0, (doubleString.IndexOf(".") +1) +2)); 

The second parameter of substring is the count, and IndexOf returns to zero-based index, so we have to add one to that before we add the 2 decimal values.

This answer is assuming that the value should NOT be rounded

Answer 4

What have you tried? It works as expected for me:

double original = 12.123456789;

double truncated = Math.Truncate(original * 100) / 100;

Console.WriteLine(truncated);    // displays 12.12

Answer 5

How about:

double num = 12.12890;
double truncatedNum = ((int)(num * 100))/100.00;

Answer 6

For vb.net use this extension:

Imports System.Runtime.CompilerServices

Module DoubleExtensions

    <Extension()>
    Public Function Truncate(dValue As Double, digits As Integer)

        Dim factor As Integer
        factor = Math.Pow(10, digits)

        Return Math.Truncate(dValue * factor) / factor

    End Function
End Module