From: Joey <rubytalk@...>
Date: 2006-08-07T16:43:34+09:00
Subject: Re: inject does not inject last value

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Its not a bug, its because thats what sum/prod are on the last iteration.
sum=3D0
[1,2,3,4,5].inject{|sum,e| sum+e }
Is:
(sum=3D0)+1
(sum=3D1)+2
(sum=3D3)+3
(sum=3D6)+4
(sum=3D10)+5

If you did:
sum=3D0
[1,2,3,4,5].inject{|sum,e| sum+=3De }
Then sum would be 15, but thats not how inject should be used.
Whats wrong with:
sum =3D [1,2,3,4,5].inject{|sum,e| sum+e } ?

j`ey
http://www.eachmapinject.com

On 8/7/06, Pe=F1a, Botp <botp@delmonte-phil.com> wrote:
>
> Hi All,
>
> inject is a powerful method in ruby. but the ff gives me surprise..
>
> irb(main):001:0> sum=3D0
> =3D> 0
> irb(main):002:0> [1,2,3,4,5].inject{|sum,e| sum+e }
> =3D> 15
> irb(main):003:0> sum
> =3D> 10
> irb(main):004:0>
> irb(main):006:0> RUBY_VERSION
> =3D> "1.8.5"
> irb(main):007:0> prod=3D1
> =3D> 1
> irb(main):008:0> [1,2,3,4,5].inject(1){|prod,e| prod*e }
> =3D> 120
> irb(main):009:0> prod
> =3D> 24
>
> it seems that inject does not update accumulator (sum or prod in examples=
)
> on last iteration.
>
> tested on windows and linux.
>
> kind regards
>
>

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