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rubycaesar-cipher

Creating A Caesar Cipher in Ruby, getting an error

I am attempting to create a Caesar Cipher in Ruby for my computer science class. My friend was able to create part of the code:

def cipher(word, n)
new_word = ""
word.each_char do |i|
    n.times do
        if(i == "z")
            i = "a"
            next
        elsif(i == "Z")
            i = "A"
            next
        end
        i.next!
        i == "%" ? i = " " : ""
    end
    new_word += i   
end
puts new_word
end
cipher("phrase", 5)

Where the last line is where you would put the phrase you want to scramble, and the number is how much you want to scramble it by. One of the requirements is that we use gets.chomp to specify a phrase and amount to scramble by without editing the .rb file itself. So I came up with this:

puts "What would you like to scramble?"
word = gets.chomp
puts "How much would you like to scramble that?"
n = gets.chomp
def cipher(word, n)
new_word = ""
word.each_char do |i|
    n.times do
        if(i == "z")
            i = "a"
            next
        elsif(i == "Z")
            i = "A"
            next
        end
        i.next!
        i == "%" ? i = " " : ""
    end
    new_word += i   
end
puts new_word
end
cipher(word, n)

And I get the following error outputed when run in Terminal:

some.rb:10:in `block in cipher': undefined method `times' for "5":String (NoMethodError)
from some.rb:9:in `each_char'
from some.rb:9:in `cipher'
from some.rb:26:in `<main>'

If someone could help me figure out what I'm doing wrong, that would help me out a lot.

Solution

  • gets.chomp returns a string

    word = gets.chomp

    So word is a string, as expected, but then you call gets.chomp again, this time to get number of scrabbles that should be applied to the string. So n is a string as well.

    n = gets.chomp

    When you call the times method on n it's not defined, because it only makes sense on integers. The solution is to convert n to an integer. This should work:

    n = gets.chomp.to_i

    Update

    Documentation on the to_i method on String instances: http://ruby-doc.org/core-2.0.0/String.html#method-i-to_i