# Integer(nil) versus Float(nil) versus String(nil) **URL:** \ **Category:** ruby-talk\ **Created:** [23 August 2006 20:45 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271 "2006-08-23T20:45:05Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Christoffer\_Sawicki](https://avatars.discourse-cdn.com/v4/letter/c/bc8723/32.png) [@Christoffer\_Sawicki](https://rubytalk.org/u/Christoffer_Sawicki)\ **Post date:** [23 August 2006 20:45 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271/1 "2006-08-23T20:45:05Z")
Dear Rubyists, def x() yield rescue :error end [x { Integer(nil) }, x { Float(nil) }, x{ String(nil) }] # =\> [0, :error, ""] Isn't that a bit inconsistent? Cheers, > **···** > > -- > Christoffer Sawicki > [http://vemod.net/](http://vemod.net/) ---
**Author:** ![Robert\_K1](https://yyz1.discourse-cdn.com/flex029/user_avatar/rubytalk.org/robert_k1/32/1830_2.png) [@Robert\_K1](https://rubytalk.org/u/Robert_K1)\ **Post date:** [23 August 2006 21:30 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271/2 "2006-08-23T21:30:20Z")
Christoffer Sawicki wrote: > Dear Rubyists, > > def x() yield rescue :error end > > [x { Integer(nil) }, x { Float(nil) }, x{ String(nil) }] > # =\> [0, :error, ""] > > Isn't that a bit inconsistent? Is this better? irb(main):003:0\> nil.to\_i =\> 0 irb(main):004:0\> nil.to\_f =\> 0.0 irb(main):005:0\> nil.to\_s =\> "" Cheers   robert ---
**Author:** ![David\_Vallner](https://avatars.discourse-cdn.com/v4/letter/d/eb9ed0/32.png) [@David\_Vallner](https://rubytalk.org/u/David_Vallner)\ **Post date:** [24 August 2006 21:30 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271/3 "2006-08-24T21:30:54Z")
Christoffer Sawicki wrote: > Dear Rubyists, > > def x() yield rescue :error end > > [x { Integer(nil) }, x { Float(nil) }, x{ String(nil) }] > # =\> [0, :error, ""] > > Isn't that a bit inconsistent? > > Cheers, Probably. \ But my Java-addled brain makes me make damn sure nulls / nils don't come anywhere near I expect actual data, like into collections or numbers. If you don't rely on automagical conversion to work, it can't bite you if it doesn't. Just code explicitly. \ The to\_foo and #Foo() type conversion methods being different always confuses the heck of me, which is why I get paranoid around them. Does anyone have a link to some rationale for and explanation of the difference? David Vallner ---
**Author:** ![Rick\_DeNatale1](https://avatars.discourse-cdn.com/v4/letter/r/bbce88/32.png) [@Rick\_DeNatale1](https://rubytalk.org/u/Rick_DeNatale1)\ **Post date:** [23 August 2006 21:38 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271/4 "2006-08-23T21:38:12Z")
Well, I'd say that it confirms that the original case is an inconsistency. > **···** > > On 8/23/06, Robert Klemme \ wrote: > > > Christoffer Sawicki wrote: > > \> Dear Rubyists, > > \> > > \> def x() yield rescue :error end > > \> > > \> [x { Integer(nil) }, x { Float(nil) }, x{ String(nil) }] > > \> # =\> [0, :error, ""] > > \> > > \> Isn't that a bit inconsistent? > > > > Is this better? > > > > irb(main):003:0\> nil.to\_i > > =\> 0 > > irb(main):004:0\> nil.to\_f > > =\> 0.0 > > irb(main):005:0\> nil.to\_s > > =\> "" > > -- > Rick DeNatale > > My blog on Ruby > [http://talklikeaduck.denhaven2.com/](http://talklikeaduck.denhaven2.com/) ---
**Author:** ![Christoffer\_Sawicki](https://avatars.discourse-cdn.com/v4/letter/c/bc8723/32.png) [@Christoffer\_Sawicki](https://rubytalk.org/u/Christoffer_Sawicki)\ **Post date:** [28 August 2006 19:36 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271/5 "2006-08-28T19:36:24Z")
> Probably. > > \ > But my Java-addled brain makes me make damn sure nulls / nils don't come > anywhere near I expect actual data, like into collections or numbers. If > you don't rely on automagical conversion to work, it can't bite you if > it doesn't. Just code explicitly. > \ That's definitely a valid point, but slightly irrelevant. > The to\_foo and #Foo() type conversion methods being different always > confuses the heck of me, which is why I get paranoid around them. Does > anyone have a link to some rationale for and explanation of the difference? Integer/Float are usually considered to be the \*strict\* equivalents of to\_i/to\_f. Try to feed them non-number strings and you'll see. I don't know anything more about them though. 🙂 Anyway, I was a bit puzzled over these two things on Integer/Float: 1) Them accepting nil at all 2) The (IMHO) inconsistency I can accept both things as they are, since nothing says they should act the way I except them to, but I thought it could be good to bring it up. Cheers, > **···** > > On 8/24/06, David Vallner \ wrote: > > -- > Christoffer Sawicki > [http://vemod.net/](http://vemod.net/) ---
**Author:** ![Forum](https://avatars.discourse-cdn.com/v4/letter/f/43a26b/32.png) [@Forum](https://rubytalk.org/u/Forum)\ **Post date:** [28 August 2006 19:59 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271/6 "2006-08-28T19:59:40Z")
> \> Probably. > \> > \> \ > \> But my Java-addled brain makes me make damn sure nulls / nils don't come > \> anywhere near I expect actual data, like into collections or numbers. If > \> you don't rely on automagical conversion to work, it can't bite you if > \> it doesn't. Just code explicitly. > \> \ > > That's definitely a valid point, but slightly irrelevant. Well it is your thread but I understand and agree with David that the nil (do not call it null on that list though 😉 in a conversion is troubeling. I read him that way that by banning it a part of your inconsistency will go away, do you agree? > The to\_foo and #Foo() type conversion methods being different always > \> confuses the heck of me, which is why I get paranoid around them. Does > \> anyone have a link to some rationale for and explanation of the > difference? > > Integer/Float are usually considered to be the \*strict\* equivalents of > to\_i/to\_f. Are they? So far I have never heared that claim. [module Kernel - RDoc Documentation](http://www.ruby-doc.org/core/classes/Kernel.html#M002003) says the contrary. I do not necessarily think that is good, but that is how it is documented. Try to feed them non-number strings and you'll see. No you will not, "x".to\_i Integer("x") I don't > know anything more about them though. 🙂 > > Anyway, I was a bit puzzled over these two things on Integer/Float: > > 1) Them accepting nil at all > 2) The (IMHO) inconsistency > > I can accept both things as they are, since nothing says they should > act the way I except them to, but I thought it could be good to bring > it up. I too hope that behavior will go away. Cheers, > -- > Christoffer Sawicki > [http://vemod.net/](http://vemod.net/) Robert > **···** > > On 8/28/06, Christoffer Sawicki \ wrote: > > > On 8/24/06, David Vallner \ wrote: > > -- > Deux choses sont infinies : l'univers et la bêtise humaine ; en ce qui > concerne l'univers, je n'en ai pas acquis la certitude absolue. > > - Albert Einstein ---
**Author:** ![Christoffer\_Sawicki](https://avatars.discourse-cdn.com/v4/letter/c/bc8723/32.png) [@Christoffer\_Sawicki](https://rubytalk.org/u/Christoffer_Sawicki)\ **Post date:** [2 September 2006 18:28 UTC](https://rubytalk.org/t/integer-nil-versus-float-nil-versus-string-nil/30271/7 "2006-09-02T18:28:23Z")
Hello! > \> > \> \> Probably. > \> \> > \> \> \ > \> \> But my Java-addled brain makes me make damn sure nulls / nils don't come > \> \> anywhere near I expect actual data, like into collections or numbers. If > \> \> you don't rely on automagical conversion to work, it can't bite you if > \> \> it doesn't. Just code explicitly. > \> \> \ > \> > \> That's definitely a valid point, but slightly irrelevant. > > Well it is your thread but I understand and agree with David that the nil > (do not call it null on that list though 😉 > in a conversion is troubeling. > I read him that way that by banning it a part of your inconsistency will go > away, do you agree? Yes, I agree. (But the inconsistency is still there.) 🙂 Just for the record, I discovered the behaviour when using FasterCSV (that emits nil for empty cells) and Integer(x) as a kind of assertion. > \> The to\_foo and #Foo() type conversion methods being different always > \> \> confuses the heck of me, which is why I get paranoid around them. Does > \> \> anyone have a link to some rationale for and explanation of the > \> difference? > \> > \> Integer/Float are usually considered to be the \*strict\* equivalents of > \> to\_i/to\_f. > > Are they? So far I have never heared that claim. > [http://www.ruby-doc.org/core/classes/Kernel.html#M002003](http://www.ruby-doc.org/core/classes/Kernel.html#M002003) says the contrary. > I do not necessarily think that is good, but that is how it is documented. When discussing this issue on #ruby-lang the general concensus was that Integer/Float are indeed stricter versions of to\_i/to\_f. The Pickaxe says "A call to Integer will work wonders (and will throw an exception if the input isn't a well-formed integer)". I should also note that the documentation for Kernel#Integer in the Pickaxe actually has "Integer(nil) =\> 0" as an example. > Try to feed them non-number strings and you'll see. > > No you will not, "x".to\_i Integer("x") "x".to\_i =\> 0 Integer("x") # ArgumentError: invalid value for Integer: "x" Isn't that just what I meant? > \> I don't > \> know anything more about them though. 🙂 > \> > \> Anyway, I was a bit puzzled over these two things on Integer/Float: > \> > \> 1) Them accepting nil at all > \> 2) The (IMHO) inconsistency > \> > \> I can accept both things as they are, since nothing says they should > \> act the way I except them to, but I thought it could be good to bring > \> it up. > > I too hope that behavior will go away. Thanks, > **···** > > On 8/28/06, Robert Dober \ wrote: > > > On 8/28/06, Christoffer Sawicki \ wrote: > > \> On 8/24/06, David Vallner \ wrote: > > -- > Christoffer Sawicki > [http://vemod.net/](http://vemod.net/)