Question

I have a string of values separated by commas, whose order isn’t important, but the uniqueness of the values is. I want to add values to the string, and I end up with something like

jruby-1.6.7 :009 > ("1,2,3,1".split(",").to_set << "1" << "4").to_a.join ","
  => "1,2,3,4" 

which is effective, but looks terrible and goes string -> array -> set -> array -> string, which is no doubt not efficient either. What’s the simple way to do this?

Answer 1

you can use | (union) operator.
e.g.

[ "1", "2", "3" ,"1"] | [ "1", "4"] 

which shall return,

["1","2","3","4"]

| (union operator) wont work on strings. so in your case, you can use

"1,2,3,4".split(",") | "1,4".split(",")

=> [“1”, “2”, “3”, “4”]