Handling Ruby Case Statement - ruby

Question

I tried to rewrite the "if/else statement" in the following piece of code by replacing it with a "case" statement, and I am deadly stuck with it for a few hours - what am I missing?
puts "Welcome to 'Guess My Number!'"
print "What is your name?"
input = gets
name = input.chomp
puts "Welcome, #{name.upcase!}!"
puts "I've got a random number between 1 and 100!"
puts "Can you guess it?"
target = rand(100) + 1
num_guesses = 0
guessed_it = false
until num_guesses == 10 || guessed_it
remaining_guesses = 10 - num_guesses
puts "You've got #{remaining_guesses.to_s} guesses left!"
print "Make a guess, put down a number: "
guess = gets.chomp.to_i
num_guesses = num_guesses + 1
end
puts case verification
when guess < target
then "Ooops. Your guess was LOW."
when guess > target
then "Ooops. Your guess was HIGH."
when guess < -1
then puts "Oooops. You have entered a number lower that 1!"
when guess > 100
then puts "Oooops. You have entered a number higher than 100!"
when guess =~ /^([w])/
then puts "Ooops. Looks like you have entered a non numeric
value!"
when guess == String
then puts "Oooops! Looks like you have entered a non numeric
value"
when guess == target
then puts "Good job, #{name}!"
puts "You guessed my number in #{num_guesses} guesses!"
guessed_it = true
end
unless guessed_it
puts "Sorry, you didn't get my number. My number was #{target}."
end
The "case statement" was used to replace and enhance the logic of the following if else statement:
if guess < target
puts "Ooops. Your guess was LOW."
elsif guess > target
puts "Ooops. Your guess was HIGH."
elsif guess == target
puts "Good job, #{name}!"
puts "You guessed my number in #{num_guesses} guesses!"
guessed_it = true
end

Answer 1

Your problem is that you're using the form of case with the optional condition, but you're using when clauses as if you were using the condition-less case.
puts case
when guess < target
"Ooops. Your guess was LOW."
should work.
Further explanation:
using case without a condition, the earliest when branch with a truthy expression is executed. This is what you want here.
But you were using case with verification. In this case, all branches are compared to verification, and the first branch where verification === branch condition is true is executed.
Since in your example I'm guessing verification is always nil, and all your branches' conditions are always true or false, no branch will ever get executed.

Answer 2

You can use a case statement like so:
class String
def green;"\e[32m#{self}\e[0m";end
def yellow;"\e[33m#{self}\e[0m";end
def cyan;"\e[36m#{self}\e[0m";end
def bg_blue;"\e[44m#{self}\e[0m";end
def bold;"\e[1m#{self}\e[22m";end
def underline;"\e[4m#{self}\e[24m";end
def border(num);"\n#{'-' * num}\n#{self}\n#{'-' * num}\n";end
end
puts;puts "Welcome to 'Guess My Number!'".bold.bg_blue;puts
print 'What is your name? '.green
name = gets.chomp
puts "\nWelcome, #{name.upcase!}!\n".cyan.underline
puts "I've got a random number between 1 and 100!\nCan you guess it?".border(44)
target = rand(100) + 1
num_guesses = 0
guessed_it = false
until num_guesses == 10 || guessed_it
remaining_guesses = 10 - num_guesses
puts "\nYou've got #{remaining_guesses} guesses left!\n"
puts;print 'Make a guess, put down a number: '
guess = gets.chomp
case guess.to_i
when (1...target)
puts 'Ooops. Your guess was LOW'.yellow.border(26)
when (target + 1..100)
puts 'Ooops. Your guess was HIGH'.yellow.border(26)
when target
puts; puts; puts
puts "Good job, #{name}!".bold.green
puts 'You guessed my number in ' + "#{num_guesses} guesses!".cyan
puts; puts; puts
guessed_it = true
else
puts "Oooops. You didn't enter a number from 1 to 100".yellow.border(47); puts
end
num_guesses += 1
end
unless guessed_it
puts;puts;puts "Sorry, you didn't get my number. My number was #{target}.".yellow;puts
end

Answer 3

Thanks a lot to everybody! With your invaluable help I managed to regain patience in my soul and satisfaction from this small task :) My mistake is that I violated the rules of common sense by trying to run several pieces of code in a wrong sequence. I moved the case statement inside the until loop and now all I have to do is correct the mistakes in particular when/then statements. It works :)
until num_guesses == 10 || guessed_it
remaining_guesses = 10 - num_guesses
puts "You've got #{remaining_guesses.to_s} guesses left!"
print "Make a guess, put down a number: "
guess = gets.chomp.to_i
num_guesses = num_guesses + 1
puts case
when guess < target
then "Ooops. Your guess was LOW."
when guess > target
then "Ooops. Your guess was HIGH."
when guess < -1
then puts "Oooops. You have entered a number lower that 1!"
when guess > 100
then puts "Oooops. You have entered a number higher than 100!"
when guess =~ /^([w])/
then puts "Ooops. Looks like you have entered a non numeric value!"
when guess == String
then puts "Oooops! Looks like you have entered a non numeric value"
when guess == target
then puts "Good job, #{name}!"
puts "You guessed my number in #{num_guesses} guesses!"
guessed_it = true
end
end
unless guessed_it
puts "Sorry, you didn't get my number. My number was #{target}."
end