On 21.11.2006 08:18, William James wrote:
> Li Chen wrote:
>> Hi all,
>>
>> I want to build a new array from an old one with every element being
>> duplicated except the first and last element. And here are my codes. I
>> wonder if this is a real Ruby way to do it.
> 
>>> array=[1,2,3,4,5,6,7,8,9,10]
> => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>>> array.zip(array).flatten[1..-2]
> => [1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10]

That's cute!  I have another one with #inject (of course):

irb(main):007:0> arr=(1..10).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
irb(main):008:0> copy=[]
=> []
irb(main):009:0> arr.inject{|a,b| copy << a << b; b}
=> 10
irb(main):010:0> copy
=> [1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10]

Kind regards

	robert