I want to convert this string: 0.55000000000000004 to this double: 0.55.
How to do that?
you can use this code to reduce precision part:
double m = Math.Round(0.55000000000000004,2);
Result would be : 0.55
Is a string or a double?
If it is a string:
double d = double.Parse(s,CultureInfo.InvariantCulture);
string s=string.Format("{0:0.00}",d);
if it is already a double just format using the second line.
There is no double 0.55 - the number cannot be accurately represented as a binary fraction. Which is probably the reason why you got that long string in the first place. You should probably be using the decimal type instead of double.
Read The Floating-Point Guide to understand why.
Related
I've tried converting the double value into a string and using the Replace() method
to replace the ',' to '.'.
This works well but only when the trailing digits are not zero, I need zeros in my string, even if the value is 1234.0. This worked well for the decimal values. I have tried to convert the double to decimal but I lose the decimal digits if there are zeros.
I know I'm missing something. I would be grateful for some suggestions.
This would depend on the language. An example in C#
d.ToString("0.00");
Would produce a double with 2 decimal places nomatter the values (zero or otherwise).
If this is in Java, check out the NumberFormat class's setMinimumFractionDigits() method.
Example:
double d1 = 2.5;
double d2 = 5.0;
NumberFormat nf = NumberFormat.getInstance();
nf.setMinimumFractionDigits(2);
String d1s = nf.format(d1);
String d2s = nf.format(d2);
System.out.println("d1s: " + d1s + " and d2s: " + d2s);
produces
d1s: 2.50 and d2s: 5.00
...and in Fortran, you could do something like: :-)
write(*,110) x
110 format (F5.3)
(guess we really have to know what language is being used...)
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Possible Duplicate:
Reading a double value from a string
I have a problem with converting my String into a double, I always get strange results.
I want to convert the following string:
string Test = "17828.571428571";
I tried it like this (because it normally works):
Double _Test = Convert.ToDouble(Test);
Result is: 17828571428571 (without the dot, lol)
I need it as a double, to Math.Round() afterwards, so I have 17828 in my example.
My second idea was to split the string, but is that really the best method? :S
Thanks for helping me!
Finn
Use InvariantCulture
Double _Test = Convert.ToDouble(Test,CultureInfo.InvariantCulture);
EDIT: I believe your current culture is "German" de-DE, which uses , for floating point.
Tried the following code. You may also use NumberFormatInfo.InvariantInfo during conversion.
string Test = "17828.571428571";
System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("de-DE");
double d = Convert.ToDouble(Test);
double d2 = Convert.ToDouble(Test, CultureInfo.InvariantCulture);
double d3 = Convert.ToDouble(Test, NumberFormatInfo.InvariantInfo);
string Test2 = "17828,571428571"; //Notice the comma in the string
double d4 = Convert.ToDouble(Test2);
Console.WriteLine("Using comma as decimal point: "+ d4);
Output: (Notice the comma in the output)
Wihtout Invariant: 17828571428571
With InvariantCulture: 17828,571428571
With NumberFormatInfo.InvariantInfo: 17828,571428571
Using comma as decimal point: 17828,571428571
double _Test = double.Parse(Test,CultureInfo.InvariantCulture);
You need to set the format provider of the conversion operation to invariant.
Try Double.TryParse or Double.Parse if you are sure there is the correct format
EDIT: But take care of the format. as example if you are german you need to type 140,50 and not 140.50 because 140.50 would be 14050.
Or you pass as parameter that you dont care of culture (see other posts).
I need help converting a string to double with 7 decimals. I have a string "00000827700000" and need it converted to 82.77
Tried using String.Format() with {0:N7} without success.
It looks like you could use:
decimal x = decimal.Parse(text.Substring(0, 7) + "." +
text.Substring(7),
CultureInfo.InvariantCulture);
That would actually parse it to 82.7700000, as decimal preserves trailing zeroes (to an extent) but maybe that's good enough? It not, you could change the second argument to
text.Substring(7).TrimEnd('0')
Note that I'd strongly recommend you to at least consider using decimal instead of double. You haven't explained what this value represents, but if it's stored as decimal figures which you need to preserve, it smells more like a decimal to me.
Based on the edit, it could be simplified as
var text = "00000827700000";
var x = decimal.Parse(text, CultureInfo.InvariantCulture) / 10000000;
Console.Write(String.Format("{0:N7}", x));
As I'm working on C#, I have one field named 'Amount'.
double amount = 10.0;
So, I want the result like '10.0' after converting it to string.
If my value
amount = 10.00, then I want result '10.00' after converting it to string.
So, Basically I want exact result in string as it is in double type. (With precisions).
Thanks in advance.
string result = string.Format( "{0:f2}", amount );
What you ask is not possible. A double in C# is a simple 64-bit floating-point value. It doesn't store precision. You can print your value with one decimal places, or two, as other answers describe, but not in a way that's "preserves" the variable's original precision.
string amountString = amount.ToString("N2");
"N2" is the format string used as the first parameter to the .ToString() method.
"N" stands for number, and 2 stands for the number of decimal places.
More on string format's here:
http://msdn.microsoft.com/en-us/library/dwhawy9k.aspx
As #Michael Petratta points out, double doesn't carry with it the precision of the input. If you need that information, you will need to store it yourself. Then you could reconstuct the input string doing something like:
static public string GetPrecisionString( double doubleValue, int precision)
{
string FormattingString = "{0:f" + precision + "}";
return string.Format( FormattingString, doubleValue);
}
I have a number like so: 4.47778E+11
Can anyone give me a way of converting that into its number representation easily in c#?
Thanks
string s = "4.47778e+11";
double d = double.Parse(s);
or
string s = "4.47778e+11";
if (double.TryParse(s,out d))
{
// number was parsed correctly
}
or for internationalization
double.Parse("4.47778e+11", System.Globalization.NumberStyles.Float, System.Globalization.CultureInfo.InvariantCulture);
Try this MSDN thread. It's called scientific notation by the way, and a quick google normally solves simple issues.
That's assuming you mean parsing from a string to a float, your question & title are conflicting
Use
float num = Convert.ToFloat(Convert.ToDouble(s));
But you still lose precision, floats are only precise to 7 digits, so you're better off using just the Convert.ToDouble() (precise to 15 or so digits), so you won't lose any digits in your example.
Use Convert:
double value = Convert.ToDouble("4.47778E+11");