CODEWITHSUNDEEP
ruby-on-railsrubyarrays
Rootski
Rootski

Reputation: 13

Iterating an Array by an Array (Another Ruby Word Count)

Having some trouble figuring out the logic for a ruby word count. My goal is to pass in some text, and get the total count of a certain category of words as defined in an array. So if I gave the following variables, I'd want to find out the fraction of words mentioned that have anything to do with fruit:

content = "I went to the store today, and I bought apples, eggs, bananas,
yogurt, bacon, spices, milk, oranges, and a pineapple. I also had a fruit 
smoothie and picked up some replacement Apple earbuds."

fruit = ["apple", "banana", "fruit", "kiwi", "orange", "pear", "pineapple", "watermelon"]

(I realize plural/singular is not consistent; just an example). Here's the code I've been trying:

content.strip
contentarray = content.downcase.split(/[^a-zA-Z]/)
contentarray.delete("")
total_wordcount = contentarray.size

IRB Test:

contentarray.grep("and")
=> ["and", "and", "and"]
contentarray.grep("and").count
=> 3

So then I try:

fruit.each do |i|
    contentarray.grep(i).count
end
=> ["apple", "banana", "fruit", "kiwi", "orange", "pear", "pineapple", "watermelon"]

It just returns the array, no counts. I would add them all up after if it returned any numbers. The goal is to end up with:

fruitwordcount 
=> 6 / 33

or

=> .1818181

I've tried searching and found a lot of methods saying to convert the content array to a hash count occurrences as many tutorials do, but that gives the count of every single word when I need the counts of only a subset. I can't seem to find a good way to search an array or string of words by an array of strings. I found a few articles saying to use a histogram from the Multiset gem, but that's still giving every word. Any help would be very much appreciated; please forgive my n00bery.

Upvotes: 0

Views: 141

Answers (5)

j-dexx
j-dexx

Reputation: 10406

To get just the fruits get your array - contentarray.keep_if{|x| fruit.include?(x) } then turn it into a hash count in the way you've found tutorials do.

Or just use inject on the contentarray to build the hash

contentarray.inject(Hash.new(0)) do |result, element|
  if fruit.include?(element)
    result[element] += 1
  end
  result
end

Hash.new(0) sets the default value to 0 so we can just add one

Upvotes: 0

Milan Köpke
Milan Köpke

Reputation: 1133

array#each returns the array itself as per ruby docs.

You probably want to try to give some of the other methods a try. Especially count and map look promising:

fruit.map do |f|
  contentarray.count{|content| content == f}
end

Upvotes: 0

Finks
Finks

Reputation: 1681

It's because the each method just iterates and executes the block. Use map or collect to execute the block and return an array.

result = fruit.map { |i| counterarray.grep(i).count }

Upvotes: 0

Aleksei Matiushkin
Aleksei Matiushkin

Reputation: 121000

Fruit#each just iterates the fruits, while you likely want to collect value. map comes to the rescue:

result = fruit.map do |i|
    [i, contentarray.grep(i).count]
end

Whether you need a hash of fruit ⇒ count, it’s simple:

result = Hash[result]

Hope it helps.

Upvotes: 1

cbliard
cbliard

Reputation: 7262

The method you are looking for is map, not each: each executes the block for each element in the array, and then returns the original array. map creates a new array containing the values returned by the block.

fruit.map do |i|
    contentarray.grep(i).count
end
=> [1, 0, 1, 0, 0, 0, 1, 0]

Upvotes: 0

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