Given an array, returns a hash

Question

Write a method, which given an array, returns a hash whose keys are words in the array and whose values are the number of times each word appears.

arr=["A", "man", "a", "plan", "a", "canal","Panama"]
# => {'a' => 3, 'man' => 1, 'canal' => 1, 'panama' => 1, 'plan' => 1}

How do I achieve that? Here's my code:

hash={}
arr.each do |i|
    hash.each do |c,v|
       hash[c]=v+1
    end
end

What does this have to do with regex? And what do you need help with? — BoltClock, Oct 20 '12 at 07:18
See this post: http://stackoverflow.com/questions/569694/count-duplicate-elements-in-ruby-array — SwiftMango, Oct 20 '12 at 07:22

score 3 · Accepted Answer · answered Oct 20 '12 at 07:23

3

hash = arr.inject({}) do |hash, element| 
  element.downcase!
  hash[element] ||= 0
  hash[element] += 1
  hash
end

answered Oct 20 '12 at 07:23

Brendan Benson

score 3 · Answer 2 · edited Oct 20 '12 at 08:34

3

arr.inject(Hash.new(0)){|h,k| k.downcase!; h[k] += 1; h}

edited Oct 20 '12 at 08:34

Sklivvz

answered Oct 20 '12 at 07:24

xdazz

1

could simplify to `{ |h,k| h[k.downcase] += 1; h }` for the inject? – Rym Oct 20 '12 at 10:15

score 0 · Answer 3 · answered Oct 20 '12 at 15:56

0

arr = ["A", "man", "a", "plan", "a", "canal","Panama"]
r = {}
arr.each { |e| e.downcase!; r[e] = arr.count(e) if r[e].nil? }

Output

p r
#==> {"a"=>3, "man"=>1, "plan"=>1, "canal"=>1, "panama"=>1}

answered Oct 20 '12 at 15:56

thebugfinder

3 Answers3