void replaceRange(int start, int end, Iterable<E> replacement)

Removes the objects in the range start inclusive to end exclusive and inserts the contents of replacement in its place.

List<int> list = [1, 2, 3, 4, 5];
list.replaceRange(1, 4, [6, 7]);
list.join(', '); // '1, 6, 7, 5'

The provide range, given by start and end, must be valid. A range from start to end is valid if 0 <= start <= end <= len, where len is this list's length. The range starts at start and has length end - start. An empty range (with end == start) is valid.

This method does not work on fixed-length lists, even when replacement has the same number of elements as the replaced range. In that case use setRange instead.

Source

void replaceRange(int start, int end, Iterable<E> replacement);