CODEWITHSUNDEEP
rubyternary-operatorproc
Cities
Cities

Reputation: 163

Ruby - Is it possible to use a ternary operator in a proc?

I'm going through TestFirst.org's Ruby course, and I ran into a coding challenge that required me to construct a method "titleize" that capitalizes every word in a string except 'little words'.

The following code solves the problem.

def titleize(words)
  little_words = %w[a an the and but or for nor on at to from by over]

  capitalizer = Proc.new do |word|
    if little_words.include? word
      word
    else
      word.capitalize
    end
  end

  words.split.map(&capitalizer)*' '
end

I originally tried using the following proc.

capitalizer = Proc.new { |word| little_words.include? word ? word : word.capitalize }

However, this proc only returned truth values. The truth values came from whether or not the word being tested was included in the little_words array. This leads me to believe that the proc is returning before it even evaluates the code to the right of the question mark.

I read the Ruby documentation for both procs and the ternary operator, but I could find nothing regarding whether or not the two can be used together.

I searched Stack Overflow for "proc ruby ternary" and read through the similar questions that popped up as I began to post this question. I couldn't find anything there either.

And so, I come to you, the geniuses of Stack Overflow. I have a question.

In Ruby, can one use a ternary operator in a proc?

(and if so, why didn't my little proc work?)

Upvotes: 0

Views: 199

Answers (1)

seph
seph

Reputation: 6076

Try:

capitalizer = Proc.new { |word| little_words.include?(word) ? word : word.capitalize }

That should work.

Upvotes: 3

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