debug_1

list = {'yvr' => 'Vancouver', 'yba' => 'Banff', 'yyz' => 'Toronto', 'yxx' => 'Abbotsford', 'ybw' => 'Calgary'}

# Why is it returning nil instead of first element of the list above
puts list.first

debug_2

def average(numbers)
  sum = 0
  if numbers.empty?
    return nil
  end
  numbers.each do |num|
    sum += num.to_i
  end
  sum.to_f / numbers.size
end

## TEST HELPER METHOD
def test_average(array = nil)
  print "avg of #{array.inspect}:"
  result = average(array)
  p result
end

## TEST CODE
test_average([4,5,6]) # => 5
test_average([15,5,10]) # => 10

# Should treat string like number
test_average([15,'5',10]) # => 10

# Should show decimal value
test_average([10, 5]) # => 7.5 instead of just 7

# Watch out! Even tests can have bugs!
test_average([9, 5, 7])

# Empty set should return nil, not throw an error
test_average([]) # => nil

# Non-existent set should return nil
test_average() # => nil

# BONUS: Should ignore nils in the set
#test_average([9,6,nil,3]) # => 6

debug_3

def sum(list)
  sum = 0
  list.each do |ele|
  sum += ele
  end
  sum
end

list1 = [16,21,31,42,55]

# 1. The following should return 165 instead of an error
puts sum(list1)

# 2. How would you refactor it using an enumerable method other than each? Examples of enumerables: map, select, inject, reject, detect.
def sum1(list)
  sum = 0
  list.map{|n| sum += n}
  sum 
end

puts sum1(list)

debug_4

def char_count(list)
  letters = {}
  list.each do |word|
    word.split('').each { |letter| 
      if letters[letter].nil? 
        letters[letter] = 1
      else 
        letters[letter] += 1
      end }
  end
  letters
end

puts char_count(['apples', 'oranges', 'hipsters', 'are', 'same'])