- Boolean
- String
- Fixnum
- Float
- Array
- Hash
- defining
- scope
- invoking
- required parameters
- Creating
- Instance methods
- Class methods
- if/unless
- while
- each
- case
- pry
- Gemfile/bundle
- blocks
- begin/rescue/end
- raise
- modules
- recursion
- regex
- Rspec (and associated tools)
- Making your own gem
- symbol to proc