Array.length
size_t length() @property constReturns the number of elements in the array.
Complexity: 1.
void length(size_t newLength) @propertySets the number of elements in the array to newLength. If newLength is greater than length, the new elements are added to the end of the array and initialized with false.
Complexity: Guaranteed abs(length - newLength) if capacity >= newLength. If capacity < newLength the worst case is newLength.
Postcondition: length == newLength