24 Spread in collections

... inserts the elements of an iterable at one position in a collection literal.

main() {
  List<String> middle = ["run", "check"]
  List<String> tail = ["share"]
  List<String> steps = ["read", ...middle, "change", ...tail]
  printLine(steps.size())
  printLine(steps[0])
  printLine(steps[2])
  printLine(steps[3])
  printLine(steps[4])
}

Expected output:

5
read
check
change
share

The middle list contributes run and check in order, and tail contributes share at the end. Neither source list becomes one nested element.

Try it: Spread an empty list and observe the new size.

Precise rules: Reference.