Misbehaving Case Statement

Question

I'm messing around in Ruby some more. I have a file containing a class with two methods and the following code:

if __FILE__ == $0 seq = NumericSequence.new puts "\n1. Fibonacci Sequence" puts "\n2. Pascal\'s Triangle" puts "\nEnter your selection: " choice = gets puts "\nExcellent choice." choice = case when 1 puts "\n\nHow many fibonacci numbers would you like? " limit = gets.to_i seq.fibo(limit) { |x| puts "Fibonacci number: #{x}\n" } when 2 puts "\n\nHow many rows of Pascal's Triangle would you like?" n = gets.to_i (0..n).each {|num| seq.pascal_triangle_row(num) \ {|row| puts "#{row} "}; puts "\n"} end end

How come if I run the code and supply option 2, it still runs the first case?

Mladen Jablanović · Accepted Answer · 2010-07-12 19:52:43Z

5

Your case syntax is wrong. Should be like this:

case choice when '1' some code when '2' some other code end

Take a look here.

You also need to compare your variable against strings, as gets reads and returns user input as a string.

answered Jul 12, 2010 at 19:52

Mladen Jablanović

44.2k13 gold badges92 silver badges113 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

glenn jackman Over a year ago

Don't forget to chomp: case choice.chomp

bta Over a year ago

Another good example for Ruby case statements: ruby-doc.org/docs/ProgrammingRuby/html/tut_expressions.html#S5

glenn jackman · Accepted Answer · 2010-07-12 19:56:51Z

Your bug is this: choice = case should be case choice.

You're providing a case statement with no "default" object, so the first clause, when 1, always returns true.

Effectively, you've written: choice = if 1 then ... elsif 2 then ... end

And, as Mladen mentioned, compare strings to strings or convert to int: choice = gets.to_i

Collectives™ on Stack Overflow

Misbehaving Case Statement

2 Answers 2

2 Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Related