Manipulating Strings and Arrays in Ruby

I've got:

@fruit = ["Apples, Oranges, Bananas", "Apples", "Bananas, Pears", "Bananas, Apples, Pears", "Pears"]

I want to do two different things with this, first turn it into a pure array with only on开发者_StackOverflowe instance of each:

["Apples", "Oranges", "Bananas", "Pears"]

Secondly I want to be able to determine how many of a given instance there are in the array:

@fruit.count("Apples") = 3

Thirdly, is it possible to order the array by the number of instances:

@fruit.sort = ["Apples", "Apples", "Apples", "Bananas", "Bananas", "Bananas", "Pears", "Pears", "Pears", "Oranges"]

What array/string functions would I have to use to do this?

arr = ["Apples, Oranges, Bananas", "Apples", "Bananas, Pears", "Bananas, Apples, Pears", "Pears"]

hsh = Hash.new { |h, k| h[k] = 0 }

arr.each do |str|
  fruits = str.split(/, /)
  fruits.each do |fruit|
    hsh[fruit] += 1
  end
end

p hsh.keys
# => ["Apples", "Oranges", "Bananas", "Pears"]

hsh.keys.each { |fruit| puts "#{fruit}: #{hsh[fruit]}" }
# => Apples: 3
# => Oranges: 1
# => Bananas: 3
# => Pears: 3

@fruit = ["Apples, Oranges, Bananas", "Apples", "Bananas, Pears", "Bananas, Apples, Pears", "Pears"]

@fruits = @fruit.map{|f| f.split(", ")}.flatten
#=>["Apples", "Oranges", "Bananas", "Apples", "Bananas", "Pears", "Bananas", "Apples", "Pears", "Pears"]
@fruits.uniq
#=> ["Apples", "Oranges", "Bananas", "Pears"]
@fruits.count{|f| f=="Apples"}
#=>3

A hash is the better data structure to do this:

@fruit = ["Apples, Oranges, Bananas", "Apples", "Bananas, Pears", "Bananas, Apples, Pears", "Pears"]

h = Hash.new

@fruit.each do |str|
  str.split(/,/).each do |f|
    f.strip!
    h[f] ||= 0
    h[f] += 1
  end
end


h.keys
 => ["Apples", "Oranges", "Bananas", "Pears"] 

h
 => {"Apples"=>3, "Oranges"=>1, "Bananas"=>3, "Pears"=>3} 

h["Apples"]
 => 3

you can then process the accumulated data in the hash to print out a sorted array if you need one.

@fruit = ["Apples, Oranges, Bananas", "Apples", "Bananas, Pears", "Bananas, Apples, Pears", "Pears"]

p @fruit.map{|f| f.split(', ') }.flatten.uniq
#=> ["Apples", "Oranges", "Bananas", "Pears"]

p @fruit.count{|f| f.include?("Apples")}
#=> 3