Converting string to double in C#
C#StringDoubleType ConversionC# Problem Overview
I have a long string with double-type values separated by #
-value1#value2#value3#
etc
I splitted it to string table. Then, I want to convert every single element from this table to double type and I get an error. What is wrong with type-conversion here?
string a = "52.8725945#18.69872650000002#50.9028073#14.971600200000012#51.260062#15.5859949000000662452.23862099999999#19.372202799999250800000045#51.7808372#19.474096499999973#";
string[] someArray = a.Split(new char[] { '#' });
for (int i = 0; i < someArray.Length; i++)
{
Console.WriteLine(someArray[i]); // correct value
Convert.ToDouble(someArray[i]); // error
}
C# Solutions
Solution 1 - C#
There are 3 problems.
1) Incorrect decimal separator
Different cultures use different decimal separators (namely ,
and .
).
If you replace .
with ,
it should work as expected:
Console.WriteLine(Convert.ToDouble("52,8725945"));
You can parse your doubles using overloaded method which takes culture as a second parameter. In this case you can use InvariantCulture
(What is the invariant culture) e.g. using double.Parse
:
double.Parse("52.8725945", System.Globalization.CultureInfo.InvariantCulture);
You should also take a look at double.TryParse
, you can use it with many options and it is especially useful to check wheter or not your string is a valid double
.
2) You have an incorrect double
One of your values is incorrect, because it contains two dots:
15.5859949000000662452.23862099999999
3) Your array has an empty value at the end, which is an incorrect double
You can use overloaded Split
which removes empty values:
string[] someArray = a.Split(new char[] { '#' }, StringSplitOptions.RemoveEmptyEntries);
Solution 2 - C#
Add a class as Public and use it very easily like convertToInt32()
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
/// <summary>
/// Summary description for Common
/// </summary>
public static class Common
{
public static double ConvertToDouble(string Value) {
if (Value == null) {
return 0;
}
else {
double OutVal;
double.TryParse(Value, out OutVal);
if (double.IsNaN(OutVal) || double.IsInfinity(OutVal)) {
return 0;
}
return OutVal;
}
}
}
Then Call The Function
double DirectExpense = Common.ConvertToDouble(dr["DrAmount"].ToString());
Solution 3 - C#
Most people already tried to answer your questions.
If you are still debugging, have you thought about using:
Double.TryParse(String, Double);
This will help you in determining what is wrong in each of the string first before you do the actual parsing.
If you have a culture-related problem, you might consider using:
Double.TryParse(String, NumberStyles, IFormatProvider, Double);
This http://msdn.microsoft.com/en-us/library/system.double.tryparse.aspx has a really good example on how to use them.
If you need a long, Int64.TryParse is also available: http://msdn.microsoft.com/en-us/library/system.int64.tryparse.aspx
Hope that helps.
Solution 4 - C#
private double ConvertToDouble(string s)
{
char systemSeparator = Thread.CurrentThread.CurrentCulture.NumberFormat.CurrencyDecimalSeparator[0];
double result = 0;
try
{
if (s != null)
if (!s.Contains(","))
result = double.Parse(s, CultureInfo.InvariantCulture);
else
result = Convert.ToDouble(s.Replace(".", systemSeparator.ToString()).Replace(",", systemSeparator.ToString()));
}
catch (Exception e)
{
try
{
result = Convert.ToDouble(s);
}
catch
{
try
{
result = Convert.ToDouble(s.Replace(",", ";").Replace(".", ",").Replace(";", "."));
}
catch {
throw new Exception("Wrong string-to-double format");
}
}
}
return result;
}
and successfully passed tests are:
Debug.Assert(ConvertToDouble("1.000.007") == 1000007.00);
Debug.Assert(ConvertToDouble("1.000.007,00") == 1000007.00);
Debug.Assert(ConvertToDouble("1.000,07") == 1000.07);
Debug.Assert(ConvertToDouble("1,000,007") == 1000007.00);
Debug.Assert(ConvertToDouble("1,000,000.07") == 1000000.07);
Debug.Assert(ConvertToDouble("1,007") == 1.007);
Debug.Assert(ConvertToDouble("1.07") == 1.07);
Debug.Assert(ConvertToDouble("1.007") == 1007.00);
Debug.Assert(ConvertToDouble("1.000.007E-08") == 0.07);
Debug.Assert(ConvertToDouble("1,000,007E-08") == 0.07);
Solution 5 - C#
You can try this example out. A simple C# progaram to convert string to double
class Calculations{
protected double length;
protected double height;
protected double width;
public void get_data(){
this.length = Convert.ToDouble(Console.ReadLine());
this.width = Convert.ToDouble(Console.ReadLine());
this.height = Convert.ToDouble(Console.ReadLine());
}
}
Solution 6 - C#
In your string I see: 15.5859949000000662452.23862099999999
which is not a double (it has two decimal points). Perhaps it's just a legitimate input error?
You may also want to figure out if your last String
will be empty, and account for that situation.