Exercise 35: Branches and Functions
You have learned if-statements, functions, and arrays. Now it's time to bend your mind. Type this in, and see if you can figure out what it's doing.
What You Should See
Here's me playing the game:
$ ruby ex35.rb You are in a dark room. There is a door to your right and left. Which one do you take? > right Here you see the great evil Cthulhu. He, it, whatever stares at you and you go insane. Do you flee for your life or eat your head? > cry Here you see the great evil Cthulhu. He, it, whatever stares at you and you go insane. Do you flee for your life or eat your head? > flee You are in a dark room. There is a door to your right and left. Which one do you take? > left There is a bear here. The bear has a bunch of honey. The fat bear is in front of another door. How are you going to move the bear? > take honey The bear looks at you then slaps your face off. Good job!
- Draw a map of the game and how you flow through it.
- Fix all of your mistakes, including spelling mistakes.
- Write comments for the functions you do not understand.
- Add more to the game. What can you do to both simplify and expand it?
- The gold_room has a weird way of getting you to type a number. What are all the bugs in this way of doing it? Can you make it better than what I've written? Look at how =~ works for clues.
Common Student Questions
- Help! How does this program work!?
- When you get stuck understanding a piece of code, simply write an English comment above every line explaining what that line does. Keep your comments short and similar to the code. Then either diagram how the code works or write a paragraph describing it. If you do that you'll get it.
- Why did you write while true?
- That makes an infinite loop.
- What does exit(0) do?
- On many operating systems a program can abort with exit(0), and the number passed in will indicate an error or not. If you do exit(1) then it will be an error, but exit(0) will be a good exit. The reason it's backward from normal Boolean logic (with 0==false) is that you can use different numbers to indicate different error results. You can do exit(100) for a different error result than exit(2) or exit(1).