(thats why he's my big brother)
On 6/15/07, James Silberbauer <[EMAIL PROTECTED]> wrote:
>
> class Array
> def inject(n)
> each { |value| n = yield(n, value) }
> n
> end
> def sum
> inject(0) { |n, value| n + value }
> end
> end
> [ 1, 2, 3, 4, 5 ].sum >> 15
>
> sum passes 0 to inject.
> inject iterates through all items in the array (array.each), placing the
> current array element's value in value
> For each value in the array, n is set to the return value of the calling
> block.
> Where the calling block is "n + value" in sum.
> It may help to think of the block as if it were "return n + value".
> yield calls sum's block with the current values of n and value. (n,
> value) ---> |n, value|
> inject returns the final value of n.
>
> Here's a better explanation:
> http://errtheblog.com/post/633
>
> James
>
>
> db wrote:
> > Hi,
> >
> > I am getting into Ruby. I've only written one program so far, after a
> > week of letting
> > the main chapters of 'Programming Ruby' sink in.
> >
> > It takes a dir of "Artist - title.mp3"s and move them to new folders
> > called "Artist"
> > Only about 7 lines of code. So it's a decent scripting language.
> >
> > But the things Gopal mentioned are what are exciting about it,
> > as mix-in's and functional programming need to be coded
> > in Java as decorators and visitors design patterns.
> >
> > Dan
> >
> > PS.
> > I am having trouble understanding the syntax of 'inject'.
> > Does anyone understand how variables get set here?:
> >
> > class Array
> > def inject(n)
> > each { |value| n = yield(n, value) }
> > n
> > end
> > def sum
> > inject(0) { |n, value| n + value }
> > end
> > def product
> > inject(1) { |n, value| n * value }
> > end
> > end
> > [ 1, 2, 3, 4, 5 ].sum >> 15
> > [ 1, 2, 3, 4, 5 ].product >> 120
> >
> >
> >
> >
> >
> >>>> Hi all
> >>>>
> >>>> Anybody using ruby out there?
> >>>>
> >>>> Brian
> >>>>
> >>>> --
> >>>> Brian Silberbauer
> >>>> Consultant
> >>>>
> >>>> +27 (0)83 566 2705
> >>>> skype: brian.silberbauer
> >>>>
> >>>> --
> >>>> No virus found in this incoming message.
> >>>> Checked by AVG Free Edition.
> >>>> Version: 7.5.472 / Virus Database: 269.8.15/848 - Release Date: 6/13/2007
> >>>> 12:50 PM
> >>>>
> >
> >
> > >
> >
> >
> >
>
> >
>
--
Brian Silberbauer
Consultant
+27 (0)83 566 2705
skype: brian.silberbauer
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