How to fix incorrect character counting code - ruby

Question

I have a question about mysterious 'e' characters appearing in my counts hash.
My initial approach was clunky and inelegant:
def letter_count(str)
counts = {}
words = str.split(" ")
words.each do |word|
letters = word.split("")
letters.each do |letter|
if counts.include?(letter)
counts[letter] += 1
else
counts[letter] = 1
end
end
end
counts
end
This approach worked, but I wanted to make it a little more readable, so I abbreviated it to:
def letter_count(str)
counts = Hash.new(0)
str.split("").each{|letter| counts[letter] += 1 unless letter == ""}
counts
end
This is where I encountered the issue, and fixed it by using:
str.split("").each{|letter| counts[letter] += 1 unless letter == " "} # added a space.
I don't understand why empty spaces were being represented by the letter 'e' or being counted at all.

Answer 1

I don't understand why empty spaces were being represented by the letter 'e' or being counted at all.
I can't duplicate the problem:
def letter_count(str)
counts = Hash.new(0)
str.split("").each{|letter| counts[letter] += 1 unless letter == ""}
counts
end
letter_count('a cat') # => {"a"=>2, " "=>1, "c"=>1, "t"=>1}
"empty spaces"? There's no such thing. A space is not empty; It's considered blank but not empty:
' '.empty? # => false
Loading the ActiveSupport extension:
require 'active_support/core_ext/object/blank'
' '.blank? # => true
spaces are valid characters, which is why they're being counted. You have to disallow them if you don't want them counted.
For reference, here's how I'd do it:
def letter_count(str)
str.chars.each_with_object(Hash.new(0)) { |l, h| h[l] += 1 }
end
letter_count('a cat') # => {"a"=>2, " "=>1, "c"=>1, "t"=>1}
A messier way would be:
def letter_count(str)
str.chars.group_by { |c| c }.map { |char, chars| [char, chars.count] }.to_h
end
Breaking that down:
def letter_count(str)
str.chars # => ["a", " ", "c", "a", "t"]
.group_by { |c| c } # => {"a"=>["a", "a"], " "=>[" "], "c"=>["c"], "t"=>["t"]}
.map { |char, chars| [char, chars.count] } # => [["a", 2], [" ", 1], ["c", 1], ["t", 1]]
.to_h # => {"a"=>2, " "=>1, "c"=>1, "t"=>1}
end

Answer 2

Ruby already has String#each_char which you could use.
def char_count(string)
counts = Hash.new(0)
string.each_char { |char|
counts[char] += 1
}
return counts
end
puts char_count("Basset hounds got long ears").inspect
# {"B"=>1, "a"=>2, "s"=>4, "e"=>2, "t"=>2, " "=>4, "h"=>1,
# "o"=>3, "u"=>1, "n"=>2, "d"=>1, "g"=>2, "l"=>1, "r"=>1}
As for why you're getting the wrong characters, are you sure you're passing in the string you think you are?