Code Kata: Fizz-Buzz
A little history
Fizz-Buzz is originally a game to help kids to learn the mathematical division by playing with numbers. If a number has a given factor, it is replaced with the matching word: "Fizz" when divisible by 3, "Buzz" when divisible by 5. Later Fizz-Buzz becomes a well-known short programming problem to select developer candidates during job interviews. Fizz-Buzz is also used as an icebreaker for adult groups, in the training, facilitation or Agile background.
Imagine the scene. You are eleven years old, and in the five minutes before the end of the lesson, your Maths teacher decides he should make his class more “fun” by introducing a “game”. He explains that he is going to point at each pupil in turn and ask them to say the next number in sequence, starting from one. The “fun” part is that if the number is divisible by three, you instead say “Fizz” and if it is divisible by five you say “Buzz”. So now your maths teacher is pointing at all of your classmates in turn, and they happily shout “one!”, “two!”, “Fizz!”, “four!”, “Buzz!”… until he very deliberately points at you, fixing you with a steely gaze… time stands still, your mouth dries up, your palms become sweatier and sweatier until you finally manage to croak “Fizz!”. Doom is avoided, and the pointing finger moves on.
So of course in order to avoid embarassment infront of your whole class, you have to get the full list printed out so you know what to say. Your class has about 33 pupils and he might go round three times before the bell rings for breaktime. Next maths lesson is on Thursday. Get coding!
Write a program that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”.
Code Kata Boilerplate for Java 8
Firstly, either you fork this repository to put all your katas in the same repository, either you create a new repository per kata and push the kata boilerplate into it. Then replace the artifact coordinates used by the build system. Name the code kata too.
Make changes only in the "kata" branch.
You can use this shortened link if needed: tinyurl.com/yyekn5rf.
You may want to commit with another identifier to publish your code later. Nothing's easier:
git config user.email "email@example.com" git config user.name "Your Pseudo" # if needed
Take advantage of your IDE shortcuts while resolving any code kata. Download and print the keymap of IntelliJ IDEA. The table below should be very useful to learn, or to learn again, the most important shortcuts.
|Theme||Must Know||Should Know||Could Know|
Ctrl + Alt + S to open settings
Ctrl + Shift + A to find action
Ctrl + Space to call basic code completion
Shift + Enter to start new line
Ctrl + Alt + L to auto-indent lines
Ctrl + Y to delete line at caret
Ctrl + Numpad +/- to expand/collapse code block
Ctrl + X to cut current line to clipboard
Ctrl + Q to call quick documentation lookup
Alt + Inser to generate code...
Shift + F6 to rename
Ctrl + Alt + M to extract method
Ctrl + Alt + V to extract variable
Ctrl + Alt + F to extract field
Ctrl + Alt + C to extract constant
Ctrl + Alt + P to extract parameter
Ctrl + N to go to class
Ctrl + Shift + N to go to file
Alt + PageUp/PageDown* to navigate back / forward
Ctrl + B to go to declaration
Ctrl + Alt + B to go to implementation(s)
Ctrl + G to go to line
|Compile and Run||
Shift + F10 / F9 to run / debug
Ctrl + Shift + F10 to run contexte configuration from editor
Alt + F7 to find usages
Ctrl + Alt + F7 to show usages
If a shortcut is marked with a '*', it is to configure in the keymap settings of the IDE.
Command Line Interface as a GUI
You can invoke a standalone JAR after building it with the "standalone" Maven profile.
mvn package -Pstandalone # to build it java -jar target/kata-standalone.jar # to use it
Updating your fork
Update your fork as follows. It is assumed you did not commit in the "master" branch. Otherwise please send me a pull request.
git fetch origin master && git rebase -p --onto origin/master master develop && git branch -f master origin/master
Definition of Done (DoD)
What should be a DoD for the code katas?
- The kata is done by applying Test-Driven Development (TDD).
- The code is versioned by applying TDDflow.
- The path to the solution is discovered according to the Transformation Priority Premise.
- The path of successive transformations is as simple as possible.
- The code coverage is greater than 95%.
- The problem to solve is described in the kata documentation.
This code kata boilerplate is distributed under the GNU GPLv3 license. The GPLv3 license is included in the LICENSE.txt file. More information about this license is available at GNU.org.