How to get words frequency in efficient way with ruby?

Question

Sample input:

\"I was 09809 home -- Yes! yes!  You was\"

and output:

{ \'yes\' => 2, \'was\' => 2, \'i\' => 1, \'home\         


        

Answer 1

class String
  def frequency
    self.scan(/[a-zA-Z]+/).each.with_object(Hash.new(0)) do |word, hash|
      hash[word.downcase] += 1
    end
  end
end

puts "I was 09809 home -- Yes! yes! You was".frequency

Answer 2

This code will ask you for input and then find the word frequency for you:

    puts "enter some text man"
text = gets.chomp
words = text.split(" ")
frequencies = Hash.new(0)
words.each { |word| frequencies[word.downcase] += 1 }
frequencies = frequencies.sort_by {|a, b| b}
frequencies.reverse!
frequencies.each do |word, frequency|
    puts word + " " + frequency.to_s 
end

Answer 3

def count_words(string)
  string.scan(/\w+/).reduce(Hash.new(0)){|res,w| res[w.downcase]+=1;res}
end

Second variant:

def count_words(string)
  string.scan(/\w+/).each_with_object(Hash.new(0)){|w,h| h[w.downcase]+=1}
end

Answer 4

def count_words(string)
  Hash[
    string.scan(/[a-zA-Z]+/)
      .group_by{|word| word.downcase}
      .map{|word, words|[word, words.size]}
  ]
 end

puts count_words 'I was 09809 home -- Yes! yes!  You was'

Answer 5

This works but I am kinda new to Ruby too. There might be a better solution.

def count_words(string)
  words = string.split(' ')
  frequency = Hash.new(0)
  words.each { |word| frequency[word.downcase] += 1 }
  return frequency
end

Instead of .split(' '), you could also do .scan(/\w+/); however, .scan(/\w+/) would separate aren and t in "aren't", while .split(' ') won't.

Output of your example code:

print count_words('I was 09809 home -- Yes! yes!  You was');

#{"i"=>1, "was"=>2, "09809"=>1, "home"=>1, "yes"=>2, "you"=>1}

Answer 6

This works, and ignores the numbers:

def get_words(my_str)
    my_str = my_str.scan(/\w+/)
    h = Hash.new(0)
    my_str.each do |s|
        s = s.downcase
        if s !~ /^[0-9]*\.?[0-9]+$/ 
            h[s] += 1
        end
    end
    return h
end

print get_words('I was there 1000 !')
puts '\n'