Re: Converting string to double: NSString or NSScanner

FROM : Michael Vannorsdel
DATE : Sun Jun 01 06:35:43 2008

Basically NSString's floatValue and doubleValue methods only work when 
the numbers use the US style dot separator (as opposed to other locale 
separators such as a comma).  If your NSString might contain non-US 
separators (or other formatting differences) you'll have to use 
NSScanner to do a localized scan of the NSString to extract the 
correct number.  If you tried to use NSString's doubleValue on 
something like "12,34" you would get 12.000.


On May 31, 2008, at 10:22 PM, Markus Spoettl wrote:

> Hello List,
>
>  I'm having troubles deciphering the documentation. I have doubles 
> stored in a text file which always use the dot "." as decimal 
> separator. When converting the strings to doubles the conversion to 
> be locale independent. The NSString:doubleValue documentation says:
>
> > This method uses formatting information stored in the non-
> localized value;
> > use an NSScanner object for localized scanning of numeric values 
> from a string.
>
> "Formatting information stored in the non-localized value" is really 
> a little cryptic - what formatting information and where is the non-
> localized value stored. The part about NSScanner indicates that 
> NSString:doubleValue is what I want, is it?