• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: doubleValue (for an NSString)
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: doubleValue (for an NSString)


  • Subject: Re: doubleValue (for an NSString)
  • From: Quincey Morris <email@hidden>
  • Date: Thu, 20 Mar 2008 16:26:31 -0700


On Mar 20, 2008, at 16:13, Boyd Collier wrote:

According to Apple's documents, the selector doubleValue returns 0.0 if the instance of an NSString that is the receiver "doesn’t begin with a valid text representation of a floating-point number." Is there a simple way to distinguish between the string 0.0, which shouldn't be considered illegitimate for my purposes, and the string (for example) X0.0 other than writing extra lines of code to distinguish one case from the other? I know I could use a scanner, but perhaps there's something simple that I'm overlooking.

As it happens, I ran into the integer version of this question yesterday. My pragmatic solution was to trim the string of whitespace, then test whether the first character was a digit (or a period, or a minus sign in your case, perhaps, but they may introduce localization concerns), and go ahead with the string conversion if it is. A bit hackish, but easier than setting up a NSScanner.


_______________________________________________

Cocoa-dev mailing list (email@hidden)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden


  • Follow-Ups:
    • Re: doubleValue (for an NSString)
      • From: John Stiles <email@hidden>
    • Re: doubleValue (for an NSString)
      • From: Alastair Houghton <email@hidden>
    • Re: doubleValue (for an NSString)
      • From: Dave Hersey <email@hidden>
References: 
 >doubleValue (for an NSString) (From: Boyd Collier <email@hidden>)

  • Prev by Date: Re: Simple messages problem
  • Next by Date: Re: doubleValue (for an NSString)
  • Previous by thread: doubleValue (for an NSString)
  • Next by thread: Re: doubleValue (for an NSString)
  • Index(es):
    • Date
    • Thread