wrong number of arguments and hash issues - ruby

Question

I am trying to make a method that counts the number of times it uses a word from a dictionary and is returned as a hash. Here's my code now:
def substrings(words, dictionary)
hash = {}
substrings.downcase!
dictionary.each do |substring|
words.each do |word|
if word.include? substring +=1
end
end
end
hash.to_s
end
dictionary = ["below", "down", "go", "going", "horn", "how", "howdy", "it", "i", "low", "own", "part", "partner", "sit"]
words = "below"
substrings(words, dictionary)
And I get this error:
wrong number of arguments (given 0, expected 2)
I'm looking for something like this:
=> {"below"=>1, "low"=>1}
I have tried multiple things but it never gives me that hash. I either get an undefined method error or this:
=> ["below", ["below", "down", "go", "going", "horn", "how", "howdy", "it", "i", "low", "own", "part", "partner", "sit"]]

Answer 1

Your error is caused by the line "substrings.downcase!" This is a recursive call to your substrings method which takes two arguments, and you are providing none. If this were not the case, you would still get an error, a stack overflow caused by the infinite recursion of this code.

Answer 2

This will produce the desired result, but I'm exchanging words in favor of word:
def substrings(word, dictionary)
word = word.downcase
dictionary.select { |entry| word.include?(entry.downcase) }
.group_by(&:itself)
.map { |k, v| [k, v.size] }.to_h
end
This results in:
>> dictionary = ["below", "down", "go", "going", "horn", "how", "howdy", "it", "i", "low", "own", "part", "partner", "sit"]
>> word = 'below'
>> substrings(word, dictionary)
=> {"below"=>1, "low"=>1}
And counts multiple copies of words, which although not explicitly stated, is presumably what you are after:
>> dictionary = ["below", "be", "below", "below", "low", "be", "pizza"]
>> word = 'below'
>> substrings(word, dictionary)
=> {"below"=>3, "be"=>2, "low"=>1}

Answer 3

You can use #reduce:
def substrings(sentence, dictionary)
sentence = sentence.downcase
dictionary.reduce(Hash.new(0)) do |counts,word|
counts[word] +=1 if sentence.include?(word.downcase)
counts
end
end
dictionary = ["below", "down", "go", "going", "horn", "how", "howdy", "it", "i", "low", "own", "part", "partner", "sit"]
sentence = "below"
substrings(sentence, dictionary) #=> {"below"=>1, "low"=>1}
Or #each:
def substrings(sentence, dictionary)
sentence = sentence.downcase
counts = Hash.new(0) # Makes the default value `0` instead of `nil`
dictionary.each do |word|
if sentence.include?(word.downcase)
counts[word] += 1
end
end
counts
end
dictionary = ["below", "down", "go", "going", "horn", "how", "howdy", "it", "i", "low", "own", "part", "partner", "sit"]
sentence = "below"
substrings(sentence, dictionary) #=> {"below"=>1, "low"=>1}