Question

A derived class, Sub, has a base class, Base.

Check the true statements about the design of Sub's constructor and mutators.

1)Sub's __init__() and/or its mutators, should not establish instance data attributes having the same name as those established in Base.

2)Sub's __init__() and/or its mutators, should redefine all of the instance data attributes that appear in Base.

3)Sub's __init__() and/or its mutators, are not required to make invocations to Base methods.

4)Sub's __init__() and/or its mutators, should manually test arguments for validity, intended for later processing by super() calls to Base's methods, even if Base's methods do those tests.

5)Sub's __init__() and/or its mutators that take parameters intended for the Base class attributes can and should pass those parameter values up to the Base class by invoking appropriate Base class method(s), without doing any pre-filtering.

Answer 1

1. True Subclasses only need to establish new instance data attributes, not the one that base class have

2. False Subclasses don't need to define

3. False Subclasses need to invoke Base class methods a/c to the requirement

4. False If the base class is doing the tests, Subclasses don't need to do it

5. True Subclasses can and should pass those parameter values up to the Base class.