String concatenation in Ruby

Question

I am looking for a more elegant way of concatenating strings in Ruby.

I have the following line:

source = \"#{ROOT_DIR}/\" << project <<          


        

Answer 1

I'd prefer using Pathname:

require 'pathname' # pathname is in stdlib
Pathname(ROOT_DIR) + project + 'App.config'

about << and + from ruby docs:

+: Returns a new String containing other_str concatenated to str

<<: Concatenates the given object to str. If the object is a Fixnum between 0 and 255, it is converted to a character before concatenation.

so difference is in what becomes to first operand (<< makes changes in place, + returns new string so it is memory heavier) and what will be if first operand is Fixnum (<< will add as if it was character with code equal to that number, + will raise error)