Collection Literals

Spread

...

...other flattens another iterable into the literal in place. Useful for prepending or appending.

Program

Play the program to assemble a list from a head, tail, and bookend numbers.

spread.dart 
void main() {
  var head = [1, 2];
  var tail = [3, 4];
  var all = [0, ...head, ...tail, 5];
  print(all);
}
spread `...xs` flattens `xs` into the surrounding literal.
null-aware spread Use `...?xs` to skip the spread when `xs` is null.
composition Combine literal elements with spread elements freely.