Why display the number 3.44445556 in float variable?

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when I enter the number 3.4 on the form in C # windows application into a database sql server 2005,, a number that is printed is 3.44445556.

how to change the number 3.44445556 to 3.4?

Posted 22-Mar-12 19:49pm

WebMaster

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Sergey Alexandrovich Kryukov 23-Mar-12 2:23am

Sounds strange... Float accuracy is low, but not that bad... :-)
Did you run it all under debugger, check the value immediately before getting a string representation? Could be some bug. By the way, float is used rarely, as the accuracy is often not enough, usually people use double... All System.Math is written in double only.
--SA

[no name] 23-Mar-12 3:55am

ok! thanks
after using a variable double in c# can be success, but on asp.net web service can not and will display a warning:

System.ArgumentException: Cannot convert 4,4 to System.Int32.
Parameter name: type ---> System.FormatException: Input string was not in a correct format.
at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
at System.String.System.IConvertible.ToInt32(IFormatProvider provider)
at System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider)
at System.Web.Services.Protocols.ScalarFormatter.FromString(String value, Type type)
--- End of inner exception stack trace ---
at System.Web.Services.Protocols.ScalarFormatter.FromString(String value, Type type)
at System.Web.Services.Protocols.ValueCollectionParameterReader.Read(NameValueCollection collection)
at System.Web.Services.Protocols.HtmlFormParameterReader.Read(HttpRequest request)
at System.Web.Services.Protocols.HttpServerProtocol.ReadParameters()
at System.Web.Services.Protocols.WebServiceHandler.CoreProcessRequest()

what's with double variables on a web service?

Herman<T>.Instance 23-Mar-12 4:26am

better show the code that creates the error

since the value is 4,4 in stead of 4.4 the error is found easily. You have to use globalization to prevent this. And you try to convert ToInt32() in stead of ToFloat()
and read this.

[no name] 23-Mar-12 4:52am

thanks very much, I will learn it

Sergey Alexandrovich Kryukov 23-Mar-12 11:32am

Of course. How "4,4" can represent integer?
--SA

[no name] 23-Mar-12 11:39am

no, but can represent double, this is can be running

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Praveen Kullu · Accepted Answer · 2012-03-23T00:30:00

Solution 1

Simply use Math.Round function.

Function usage:

C#

Math.Round(decimal d,int dec);

According to your Question:

C#

double num = Math.Round(3.44445556, 1);

Posted 23-Mar-12 0:30am

Praveen Kullu

Updated 23-Mar-12 1:11am

v3

Comments

[no name] 23-Mar-12 6:47am

thanks very much Mr. Kullu

[no name] 23-Mar-12 6:56am

what is the value of "d" in your program?

Shahin Khorshidnia 23-Mar-12 7:05am

My +5

Praveen Kullu 23-Mar-12 7:09am

d = 3.44445556 here.

Ajith The Great · Accepted Answer · 2012-03-23T00:50:00

Solution 2

SQL

Declare @flt as Float
Set @flt = 3.44445556
Select round(@flt,1)

OUTPUT :3.3999999999999999

HTML

AND IF YOU USE MONEY DATATYPE

SQL

Declare @flt as MONEY
Set @flt = 3.44445556
Select round(@flt,1)

OUTPUT : 3.40

BETTER TO USE MONEY DATATYPE

Hope This May Help You..

Posted 23-Mar-12 0:50am

Ajith The Great

Comments

[no name] 23-Mar-12 6:59am

thanks a lot of Mr. Ajith

Shahin Khorshidnia 23-Mar-12 7:06am

my +5

(__Aaron__) 24-Mar-12 2:06am

nice!