Array.join(“\n”) not the way to join with a newline?

Question

I have an array..

[1,2,3,4]

and I want a string containing all the elements separated by a newline..

1

2

3

4
         


        

Answer 1

A subtle error that can occur here is to use single quotes instead of double. That also has the effect of rendering the newlines as \n. So

puts a.join("\n")   # correct

is not the same as

puts a.join('\n')   # incorrect

There is an excellent write up on why this is the case here.