From: 7stud -- <bbxx789_05ss@...>
Date: 2008-03-30T15:21:20+09:00
Subject: Re: inject's pathological case...

Just Another Victim... wrote:
> I'm not sure how I feel about inject's pathological case.  What do you
> all think should happen in the following code?
> 
> 
> [2].inject {|a, i| puts i}
> 
> 
>     I might have thought that the block would never be called and the 
> method
> would return 2.
>     If the block must be called, I might expect "i" to be nil.


>     What actually happens is that the block is called and "i" is the 
> same
> thing as "a".  I did not expect this and I'm trying to figure out how 
> this
> is either consistent or useful.  Can someone clue me in to this 
> behaviour?

I'm not seeing that:

1) Two element array:

result = [2, 3].inject do |a, i|
  puts "a:#{a}"
  puts "i:#{i}"
  puts "hello"
  puts "--------"
end

puts "result=#{result}"
if result.nil?
  puts 'yes'
end

--output:--
a:2
i:3
hello
--------
result=
yes


2) One element array:

result = [2].inject do |a, i|
  puts "a:#{a}"
  puts "i:#{i}"
  puts "hello"
  puts "--------"
end

puts "result=#{result}"
if result.nil?
  puts 'yes'
end

--output:--
result=2
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