I would like to do a.each_with_object with index, in a better way than this:
a = %w[a b c]
a.each.with_index.each_with_object({}) { |arr, hash|
v,i = arr
puts "i is: #{i}, v is #{v}"
}
i is: 0, v is a
i is: 1, v is b
i is: 2, v is c
=> {}
Is there a way to do this without v,i = arr ?
In your example .each.with_index is redundant. I found this solution:
['a', 'b', 'c'].each_with_object({}).with_index do |(el, acc), index|
acc[index] = el
end
# => {0=>"a", 1=>"b", 2=>"c"}
Instead of
|arr, hash|
you can do
|(v, i), hash|
a.each.with_index.with_object and @ka8725's answer refers to each_with_object({}).with_indexYou could replace your last line with
puts "i is: %d, v is %s" % arr.reverse
but, as @sawa suggested, disambiguating the array's argument is the thing to do here. I just mention this as something to be stored away for another day.
array.each_with_index.to_h
each_with_index gives you [element, index] pairs.
to_h converts an array of pairs ([key, value]) into a H
hashdoing?each_with_object({}).with_index?!|(e,h),i|, whereeis the element of the arraya,his the hash object being created and returned andiis the index.map.with_indexis another common use ofwith_index. When you can't tackwith_indexto the end of an Enumerable method, you can precede it witheach_with_index, rather thaneach.with_index.