# Human-readable listing of array elements

**URL:** <https://rubytalk.org/t/human-readable-listing-of-array-elements/56573>\
**Category:** ruby-talk\
**Created:** [10 December 2009 14:15 UTC](https://rubytalk.org/t/human-readable-listing-of-array-elements/56573 "2009-12-10T14:15:08Z")\
**Posts on this page:** 2\
**Page:** 2

<div class="post-metadata">

**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:** [13 December 2009 11:27 UTC](https://rubytalk.org/t/human-readable-listing-of-array-elements/56573/21 "2009-12-13T11:27:56Z")

</div>

My comment referred to the "won't handle \<=" part. I demonstrated how it can be made to handle less than comparisons directly, i.e. without using ranges which is not exactly the same operation.

Cheers

&nbsp;&nbsp;robert

> **···**
>
> On 10.12.2009 18:48, Aldric Giacomoni wrote:
> 
> > Robert Klemme wrote:
> > 
> > > 2009/12/10 Aldric Giacomoni\<aldric@trevoke.net\>:
> > > 
> > > > Marnen Laibow-Koser wrote:
> > > > 
> > > > > Yes. �case won't handle\<= conditions AFAIK.
> > > > 
> > > > That is a very good point, though it does handle ranges, so "case 0..1"  
> > > > would fit this particular scenario.  
> > > > Your elsif statement is probably better suited here though.
> > > 
> > > That point is not exactly true: while it doesn't out of the box...
> > 
> > c:\\>irb  
> > irb(main):001:0\> RUBY\_VERSION  
> > =\> "1.8.7"  
> > irb(main):002:0\> 5.times { |a| case a; when 0..2 then puts "yow" else  
> > puts "nah" end }  
> > yow  
> > nah  
> > =\> 5  
> > irb(main):003:0\>
> > 
> > Alright.. Well then, I'm confused.
> 
> --  
> remember.guy do |as, often| as.you\_can - without end  
> [http://blog.rubybestpractices.com/](http://blog.rubybestpractices.com/)

---

<div class="post-metadata">

**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:** [10 December 2009 22:10 UTC](https://rubytalk.org/t/human-readable-listing-of-array-elements/56573/22 "2009-12-10T22:10:07Z")

</div>

> Benoit Daloze wrote:

> > As written in "Programming Ruby 1.9",  
> > You can really use case as if ... elsif ... else ... end
> > 
> > So, in our case:
> > 
> > if self.size \<= 1  
> > &nbsp;&nbsp;return self.to\_s  
> > elsif self.size == 2  
> > &nbsp;&nbsp;return self.join " #{conjunction} "  
> > else  
> > &nbsp;&nbsp;array = self.dup  
> > &nbsp;&nbsp;array[-1] = [conjunction, array[-1]].join ' '  
> > &nbsp;&nbsp;array.join separator # proper English usage has comma before 'and'  
> > end
> > 
> > becomes:
> > 
> > case  
> > when self.size \<= 1  
> > &nbsp;&nbsp;return self.to\_s  
> > when self.size == 2  
> > &nbsp;&nbsp;return self.join " #{conjunction} "  
> > else  
> > &nbsp;&nbsp;array = self.dup  
> > &nbsp;&nbsp;array[-1] = [conjunction, array[-1]].join ' '  
> > &nbsp;&nbsp;array.join separator # proper English usage has comma before 'and'  
> > end
> 
> Thanks, I had forgotten about that too.

Me, too.

> > Well, that's not especially better I think, but it looks cool and a little  
> > less 'procedural' to me.
> 
> It's no less procedural, and in fact it uses another line of code for no advantage that I can see.

The advantage for me is that "case" conveys a different notion: I am reminded of SQL's case which is an expression, i.e. you get a single value out of several based on conditions after "where". "if elsif else end" is more about executing different procedural sequences. The difference is less technical and more informal.

> If you truly want this to look less procedural, I think you'd need to somehow implement a polymorphic dispatch based on Array.size...but let's not go there. 🙂

Not too difficult either, let's see....

Kind regards

&nbsp;&nbsp;robert

> **···**
>
> On 12/10/2009 06:49 PM, Marnen Laibow-Koser wrote:
> 
> --  
> remember.guy do |as, often| as.you\_can - without end  
> [http://blog.rubybestpractices.com/](http://blog.rubybestpractices.com/)

[Previous page](https://rubytalk.org/t/human-readable-listing-of-array-elements/56573.md?page=1)