McTano · May 25, 2016 19:37
diff --git a/debug01.rb b/debug01.rb
 list = {'yvr' => 'Vancouver', 'yba' => 'Banff', 'yyz' => 'Toronto', 'yxx' => 'Abbotsford', 'ybw' => 'Calgary'}

 # Why is it returning nil instead of first element of the list above
 # p list[0] treats 0 as a key, not an integer index.
 # we can call the first element like so, assuming we want the value.

 #p list.values[0]

 # if we want the key, we can do it like so:

 # p list.keys[0]

 # but, again assuming we want 'Vancouver' we should probably call
 # it by the key instead:

 p list['yvr']
diff --git a/debug02.rb b/debug02.rb
 def average(numbers=[])
  sum = 0
  numbers.each do |num|
      sum += num.to_f 
  end
  sum / (numbers.size - numbers.count(nil)) unless numbers.size == 0
 end

 ## TEST HELPER METHOD
 def test_average(array=[])
  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]) #=> 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
  
diff --git a/debug03.rb b/debug03.rb
 def sum(list)
  total = 0
  list.each do |ele|
    total += ele
  end
  total
 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 sum_alt(list)
  list.inject {|sum, i| sum + i}
 end

 puts sum_alt(list1)
diff --git a/debug04.rb b/debug04.rb
 def char_count(list)
  letters = Hash.new(0)
  list.each do |word|
    word.split('').each { |letter| letters[letter] += 1 }
  end
  letters
 end

 # Why the long face(error)? 
 # 1. This should return count of each letter in the list
 # ex: { "a" => 4, "p" => 3, "l" => 1  ...}

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

 # A: caused an error when the letter was not already present as a key.

 # 2. What are the improvements you can do to above code?

 # A: added default value 0 to prevent error, which has the added benefit
 #    of allowing us to check the count of a letter which is not present in
 #    the original array and get the correct answer: 0.
diff --git a/error_example.rb b/error_example.rb
 def method1
  method2
 end

 def method2
  method3
 end

 def method3(a)
  puts a
 end

 method1
	list = {'yvr' => 'Vancouver', 'yba' => 'Banff', 'yyz' => 'Toronto', 'yxx' => 'Abbotsford', 'ybw' => 'Calgary'}

	# Why is it returning nil instead of first element of the list above
	# p list[0] treats 0 as a key, not an integer index.
	# we can call the first element like so, assuming we want the value.

	#p list.values[0]

	# if we want the key, we can do it like so:

	# p list.keys[0]

	# but, again assuming we want 'Vancouver' we should probably call
	# it by the key instead:

	p list['yvr']
	def average(numbers=[])
	sum = 0
	numbers.each do \|num\|
	sum += num.to_f
	end
	sum / (numbers.size - numbers.count(nil)) unless numbers.size == 0
	end

	## TEST HELPER METHOD
	def test_average(array=[])
	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]) #=> 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
	def sum(list)
	total = 0
	list.each do \|ele\|
	total += ele
	end
	total
	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 sum_alt(list)
	list.inject {\|sum, i\| sum + i}
	end

	puts sum_alt(list1)
	def char_count(list)
	letters = Hash.new(0)
	list.each do \|word\|
	word.split('').each { \|letter\| letters[letter] += 1 }
	end
	letters
	end

	# Why the long face(error)?
	# 1. This should return count of each letter in the list
	# ex: { "a" => 4, "p" => 3, "l" => 1 ...}

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

	# A: caused an error when the letter was not already present as a key.

	# 2. What are the improvements you can do to above code?

	# A: added default value 0 to prevent error, which has the added benefit
	# of allowing us to check the count of a letter which is not present in
	# the original array and get the correct answer: 0.
	def method1
	method2
	end

	def method2
	method3
	end

	def method3(a)
	puts a
	end

	method1