length property

int length

Returns the number of objects in this list.

The valid indices for a list are 0 through length - 1.

Implementation 

int get length {
  // Check the length honours the List contract.
  var len = JS('', '#.length', _jsObject);
  // JavaScript arrays have lengths which are unsigned 32-bit integers.
  if (JS('bool', 'typeof # === "number" && (# >>> 0) === #', len, len, len)) {
    return JS('int', '#', len);
  }
  throw new StateError('Bad JsArray length');
}
void length= (int length)

Changes the length of this list.

If newLength is greater than the current length, entries are initialized to null.

Throws an UnsupportedError if the list is fixed-length.

Implementation 

void set length(int length) {
  super['length'] = length;
}