ruby tutorial at dot install

array.rb

p "---array operator---"

# array object
sales = [5,8,4]

# replace
sales[0...2]=[1,2]
p sales # [1,2,4]

# insertion
#   -- (replace 0 objects after index 1) === insertion 
sales[1, 0] = [10,11,12]
p sales # [1, 10,11,12, 2, 4]

# deletion
#  -- (replace to empty array) === deletion
sales[0, 2] = []
p sales # [11, 12, 2, 4]

p "---array method---"

p sales.size
p sales.sort
p sales.sort.reverse

p sales.push(100)
p sales << 101 << 102

hash.rb

# hash (key value)

p "---hash operator---"
sales1 = {"taguchi" => 200, "fkoji" => 300}
p sales1["taguchi"]

sales2 = {:taguchi => 100, :fkoji => 400}
p sales2[:taguchi]

sales3 = {taguchi: 1000, fkoji: 100}
p sales3[:taguchi]


p "---hash method---"
p sales1.size
p sales1.keys
p sales1.values

# key string is not equql symbol.
p sales1.has_key?(:taguchi)
p sales2.has_key?(:taguchi)
p sales1.has_key?("taguchi")