join

join($list1, $list2, $separator:auto)

Joins together two lists into one.

Unless $separator is passed, if one list is comma-separated and one is space-separated, the first parameter’s separator is used for the resulting list. If both lists have fewer than two items, spaces are used for the resulting list.

Like all list functions, join() returns a new list rather than modifying its arguments in place.

join(10px 20px, 30px 40px) => 10px 20px 30px 40px
join((blue, red), (#abc, #def)) => blue, red, #abc, #def
join(10px, 20px) => 10px 20px
join(10px, 20px, comma) => 10px, 20px
join((blue, red), (#abc, #def), space) => blue red #abc #def