Hello.
I need to transform ["a", "b", "c", "d"] to {:a => {:b => {:c => "d" }}} ?
Any ideas ?
Thanks
views:
68answers:
4
+1
A:
I like it:
class Array
def to_weird_hash
length == 1 ? first : { first.to_sym => last(length - 1).to_weird_hash }
end
end
["a", "b", "c", "d"].to_weird_hash
What do you think?
jordinl
2010-09-09 08:43:43
What version of ruby is this valid for?
Steve Weet
2010-09-09 09:03:05
it's ruby-1.8.7
jordinl
2010-09-09 09:04:31
OK. I'm getting undefined method `from` in both 1.8.7 and 1.9.2
Steve Weet
2010-09-09 09:12:16
that's weird...
jordinl
2010-09-09 09:15:33
I'm doing it now with irb and it's not working, before I did it in script/console. Apparently the method Array#from doesn't exist... :S
jordinl
2010-09-09 09:21:03
Nice solution. I'm doing it in rails, so it is working.
retro
2010-09-09 09:55:32
Sounds like it is a ROR Monkeypatch.
Steve Weet
2010-09-09 09:56:00
yeah, too bad...
jordinl
2010-09-09 10:12:34
+4
A:
funny
ruby-1.8.7-p174 > ["a", "b", "c", "d"].reverse.inject{|hash,item| {item.to_sym => hash}}
=> {:a=>{:b=>{:c=>"d"}}}
hellvinz
2010-09-09 08:59:35
+1
A:
If you need to do it for exactly 4 elements, it's easy enought to just write it out (and quite readable too)
>> A=["a", "b", "c", "d"]
=> ["a", "b", "c", "d"]
>> {A[0].to_sym => {A[1].to_sym => {A[2].to_sym => A[3]}}}
=> {:a=>{:b=>{:c=>"d"}}}
Otherwise, this will work for variable length arrays
>> ["a", "b", "c", "d"].reverse.inject(){|a,e|{e.to_sym => a}}
=> {:a=>{:b=>{:c=>"d"}}}
>> ["a", "b", "c", "d", "e", "f"].reverse.inject(){|a,e|{e.to_sym => a}}
=> {:a=>{:b=>{:c=>{:d=>{:e=>"f"}}}}}
gnibbler
2010-09-09 09:37:15
A:
I figured it out with help on IRC.
x = {}; a[0..-3].inject(x) { |h,k| h[k.to_sym] = {} }[a[-2].to_sym] = a[-1]; x
Second way with recursive (better)
def nest(a)
if a.size == 2
{ a[0] => a[1] }
else
{ a[0] => nest(a[1..-1]) }
end
end
retro
2010-09-09 09:53:00