Shared Cards

When you create a flashcard with CodeCode Ninja, you can share it with others to help them learn. Below are a few categories with user-contributed cards. You can also "adopt" these into your own account and make them your own.


There's more to Git than just git add and git commit. These cards are full of useful Git tidbits. There's lots more you can add here, so please don't hesitate to make and share cards of your own!

  • delete a remote branch
  • grep within git log
  • Switch to previous branch
  • Git grep: Exclude directory
  • Git grep for words


These are cards with fundamentals, tips, and tricks specifically for Ruby on Rails.

  • URL for Rails routes info in dev mode
  • Routes
  • CRUD - C
  • Crud again
  • Crud - editing


These are flashcards about the basics of Ruby, regardless of whether or not you use it with Rails.

  • How to remove trailing and leading whitespaces from string?
  • pause for ten seconds
  • Using map
  • Do block syntax
  • Look for a key :b in "stuff" hash, return "moo" if you can't find it.


SQL isn't fun, but sometimes it's necessary. These cards cover some of the fundamentals of SQL, but there's lots more that could be added here.

  • given a table of movies, select the one with id 6
  • Given a table of movies, find the ones released in the years between 2000 and 2010
  • Given a table of movies, find the movies not released in the years between 2000 and 2010
  • In a table of movies, select the first 5 rows by ID
  • SQL keyword for case-insensitive exact string match


The Vim editor is notoriously difficult to get started with, but once you pick it up, it'll become an indispensable tool. One key thing (pun intended...) is to remember your keyboard shortcuts and commands. You can use CodeCode Ninja to do this.

  • Go to project root
  • Remove search highlights
  • Regex: New line
  • Repeat last colon command
  • NERDTree: Open in vertical split