Iterating over an array to create variables in ruby

Question

Is it possible to create multiple variables by iterating over an array?

For example, say I had an array called numbers = [1,2,3,4,5] and I wanted to create a series of variables called number_1, number_2,...,number_5 each equal to their respective index in the numbers array (e.g. number_1 = 1, number_2 = 2, etc.).

I tried something along the lines of the following:

numbers.each_with_index do |num, index|
  number_"#{index+1}" = num
end

But that failed.

Essentially, I would like for the iterating process to automate creating and assigning values to variables.

Thank you.

Answer 1

One way is:

instance_variable_set("@number_#{index+1}", num)

Another way is using the eval method to create an instance variable:

eval "@number_#{index+1} = #{num}"

Heads up that eval is considered a bit hacky, and doesn't work on JRuby.

(Caveat: the code above creates instance variables, not scope-level variables (a.k.a. local variables). Example: the code creates @number_1 not number_1. As far as I'm aware Ruby does not offer a straightforward way to dynamically create a scope-level variable that persists; you can create one within an eval but it goes out of scope beyond the eval.)