Help finding function -- concatenate strings with separator

I am having trouble finding a function that I am pretty sure exists. Suppose I have a vector of strings. I want to concatenate these strings into one longer string, but with a separator in-between each. Doesn’t this function exist?

In other words, the inverse of the split function.

  join([io::IO,] iterator [, delim [, last]])

  Join any iterator into a single string, inserting the given delimiter (if any) between adjacent items. If last is
  given, it will be used instead of delim between the last two items. Each item of iterator is converted to a
  string via print(io::IOBuffer, x). If io is given, the result is written to io rather than returned as a String.


  julia> join(["apples", "bananas", "pineapples"], ", ", " and ")
  "apples, bananas and pineapples"
  julia> join([1,2,3,4,5])


Thanks. Couldn’t find it using my search terms!