to_s方法返回不需要的“ \\”

Question

I wrote a method that takes an array of numbers, adds the number 2 to it, and then returns an array of strings.

def add_two(array)
  new_array = array.map{|x| "#{x} + 2 =  #{x + 2}"}
  new_array.to_s
end

The following is a test result:

I have an unwanted \\ in my return. I am trying to figure out where the \\ is coming from. Can someone point me in the right direction?

Answer 1

It is coming from to_s that you have at the end. You are converting an array of strings (which is presumably already what you want) into a single string that contains double quotations (which must be escaped by \\ ). To fix it, just remove your line with to_s .

Answer 2

Its not adding extra \\ s. \\ is escape character to escape " which is part of the result String. Here:

a = add_two(array)
# => "[\"1 + 2 =  3\", \"2 + 2 =  4\", \"3 + 2 =  5\"]"

puts a
# ["1 + 2 =  3", "2 + 2 =  4", "3 + 2 =  5"]

or directly:

puts add_two(array)
# ["1 + 2 =  3", "2 + 2 =  4", "3 + 2 =  5"]