add method
Adds value
to the end of this list,
extending the length by one.
The list must be growable.
final numbers = <int>[1, 2, 3];
numbers.add(4);
print(numbers); // [1, 2, 3, 4]
Implementation
@override
void add(T value) {
if (_list == null) {
_list = _iList!.unlock;
_iList = null; // To allow for garbage-collection.
}
_list!.add(value);
}