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The correct choice is (c) 3

Easiest explanation - There must be at least 3 levels of INHERITANCE. Otherwise if less, it will be SINGLE level inheritance or would have GOT no inheritance implemented. There must be a derived CLASS from which ANOTHER class is derived.

Right choice is (d) As many LEVELS of inheritance as required

Easy EXPLANATION - The multilevel inheritance allows any number of levels of inheritance. This is the maximum flexibility feature to MAKE the members available to all the new classes and to add their own functionalities. The code REUSABILITY is USED too.

The correct choice is (b) Each class can ACCESS only non-PRIVATE members of its parent

Best explanation: The CLASSES will be able to access only the non-private members of its parent class. The classes are using private inheritance, hence all the members of the parent class BECOME private in the derived class. In turn those won’t be allowed for further inheritance or DIRECT access outside the class.

Right ANSWER is (a) Class at 1st LEVEL

Explanation: The class with HIGHEST degree of abstraction will be the class at the 1st level. You can look at a SIMPLE example like, a CAR is more abstract than SPORTS CAR class. The level of abstraction decrease with each level as more details comes out.

The CORRECT OPTION is (b) Classes being DERIVED from other derived classes

Best explanation: Only if the class is being derived from other derived class, it can be called as multilevel inheritance. If a class is derived from another class, it is SINGLE LEVEL inheritance. There must be more than one level of inheritance.

Right choice is (a) Yes, always

To explain: The nested classes are also members of a CLASS. They BEHAVE as a used defined data type with some methods implementation. So the INHERITANCE will be as usual with the nested classes being member of BASE class and of derived class if not private.

Right option is (a) Base class constructor

To EXPLAIN I would say: The base class constructor will be called first from the OBJECT of derived class constructor. When the derived class members are to be initialized and allocated memory, the base class members should ALSO be confirmed with the memory allocation.

Right choice is (b) Multiple inheritance

The best explanation: If single inheritance is used then only feature of a single class are inherited, and if multilevel inheritance is used, the 2ND class might have use private inheritance. Hence only multiple inheritance can RESULT in derived class with more features. This is not MANDATORY but in a CASE if we CONSIDER same number of features in each class, it will result the same.

Right answer is (C) There can be more than 2 independent classes involved in single inheritance

Best EXPLANATION: If more than 2 independent classes are involved to implement the single level inheritance, it won’t be POSSIBLE as there must be only one child and one parent CLASS and none other related class.

The correct ANSWER is (d) No, the derived CLASS MUST implement those methods

The best explanation: The derived class must implement those methods. This is because the parent class is abstract and hence will have some undefined functions which has to be defined in derived classes. Since we are using single level inheritance, if derived class doesn’t implement those functions then one more class has to be there which will BECOME multi-level inheritance.

The correct option is (a) Runtime

To explain I WOULD SAY: The runtime inheritance is done when object of a class is created to call a method. At runtime the FUNCTION is searched if it is in class of object. If not, it will SEARCH in its parent classes and hierarchy for that method.

Correct answer is (a) At least 2 classes

Easy explanation - The PROGRAM will contain at least 2 classes in the SENSE of base and DERIVED classes. At least one base CLASS and one derived class must be there. TYPES of inheritance remains the same though.

Correct answer is (a) Those are 2 PAIRS of single INHERITANCE

Explanation: Since class A is DERIVED from class C and then class B is derived from class D, there are two pairs of classes which shows single inheritance. Those two pairs are INDEPENDENT of each other though.

The CORRECT OPTION is (b) One DERIVED class inherits from one base class

The BEST explanation: If only one base class is used to derive only one subclass, it is known as single level inheritance. The reason of this NAME is that we inherit the base class to one more level and stop the inheritance any further.

Right OPTION is (d) There is no limit

Easy explanation - In this case, there is no limit. All the classes going on like this will INHERIT the MEMBERS of base class, and hence the upper level inheritance won’t affect the number of classes that can go on INHERITING in this pattern.

The CORRECT choice is (a) Only 1

Easy EXPLANATION - SINCE java doesn’t support multiple inheritance, it is not possible for a class to inherit more than 1 class in java. This is the same case in C# also.

Right answer is (d) Any NUMBER of CLASSES can be inherited

The best EXPLANATION: Any class can inherit any number of classes. There is no LIMIT defined for the number of classes being inherited by a single class.

Correct CHOICE is (d) All types can have private inheritance

The best EXPLANATION: This is a COMMON TYPE of inheritance where the PROTECTED and public members of parent class become private members in child class. There is no type which doesn’t support private inheritance.

Correct choice is (b) False

To explain I would say: This is so because few CLASSES might not be involved in any type of inheritance in WHOLE PROGRAM whereas other classes might be PARTICIPATING in more than ONE type of inheritance at the same time.

Correct option is (d) MULTIPLE INHERITANCE among NESTED CLASSES, and single level for enclosing classes

Explanation: This involves the same concept of inheritance, where the nested classes also follow the inheritance RULES. The Enclosing classes are having single inheritance. Nested classes involves multiple.

The CORRECT OPTION is (B) Hybrid inheritance always contains MULTIPLE inheritance

Easiest explanation - It is not necessary to have multiple inheritance in hybrid TYPE. It can have any type together. This doesn’t have to be of specific type always.

Right option is (a) Single

The EXPLANATION is: Here all the pairs are using single inheritance. And no DIFFERENT pairs are INHERITING same classes. Hence it can’t be called hybrid or multilevel inheritance. You can say the single inheritance is used 3 times in that program.

Right CHOICE is (d) Any type, any number of times

The best EXPLANATION: Any type of inheritance can be used in any PROGRAM. There is no rule to USE only few types of inheritance. Only thing that matters is how the CLASSES are inherited and used.

Right choice is (d) More than one CLASS being PARENT of single child

Explanation: If a class inherits more than one class, it is known as multiple inheritance. This should not be REFERRED with only two or three CLASSES being INHERITED. But there must be one class which inherits more than one class to be called as multiple inheritance.

The correct option is (d) 5

To explain I would say: There are five types of INHERITANCE that are possible in C++. Single LEVEL, Multilevel, multiple, hierarchical and hybrid. Here we count hybrid also because it sometimes can bring up a new form of inheritance, Like inheritance USING multiple and hierarchical, which sometimes RESULTS in diamond problem.

The correct option is (d) It can be done both by making the visibility mode public or protected

The EXPLANATION is: It is not mandatory that you have to MAKE the visibility mode either public or protected. You can do either of those. That will GIVE you permission to inherit the PRIVATE members of BASE class.

Right answer is (a) True

To explain I would say: Consider that a variable is PRIVATE in base class and the derived class USES public INHERITANCE to inherit that class. Now if we also have a global variable of same name as that of base class private variable, neither the global variable nor the base class private variable will be accessible from derived class. This is because we can’t have 2 variables with same name in same LOCAL scope. Hence the private members are accessible but not DIRECTLY.

The correct choice is (a) BASE class constructor

Best explanation: First the base class constructor is INVOKED. When we create a derived class OBJECT, the system tries to invoke its constructor but the class is derived so first the base class must be INITIALIZED, HENCE in turn the base class constructor is invoked before the derived class constructor.

The correct ANSWER is (c) It GETS inherited privately by DEFAULT

Explanation: If the ACCESS mode is not specified during inheritance, the class is inherited privately by default. This is to ensure the security of data and to maintain OOP features. Hence it is not mandatory to specify the access mode if we want the class to be inherited privately.

The CORRECT answer is (c) Private members

Easiest explanation - Private access specifier is the most secure access mode. It doesn’t ALLOW members to be INHERITED. Even Private INHERITANCE can only INHERIT protected and public members.

Right option is (a) PUBLIC and Protected members of base class BECOMES protected members of derived class

The explanation: As the programming language rules apply, all the public and protected members of base class becomes protected members of derived class in protected ACCESS mode. It can’t be changed because it would HINDER the security of data and may ADD vulnerability in the program.

The correct answer is (c) Multiple

Best EXPLANATION: When 2 or more classes inherit the same class using multiple inheritance and then ONE more class inherits those two base classes, we get a diamond like structure. Here, ambiguity ARISES when same FUNCTION gets derived into 2 base classes and finally to 3rd level class because same NAME functions are being inherited.

Correct choice is (c) class derived_classname : access base_classname{ /*define class body*/ };

The explanation is: Firstly, keyword class should come, followed by the derived class NAME. COLON is MUST followed by access in which BASE class has to be derived, followed by the base class name. And finally the body of class. Semicolon after the body is also must.

The CORRECT OPTION is (c) One base class can be DERIVED into other two derived classes or more

Best explanation: One base class can be derived into the other two derived classes or more. If only one class GETS derived by only 2 other classes, it is also hierarchical INHERITANCE, but it is not a mandatory condition, because any number of derived classes can be there.

The correct choice is (d) JAVA

The explanation is: Java doesn’t support multiple inheritance. But that feature can be implemented by using the interfaces concept. Multiple inheritance is not supported because of diamond PROBLEM and similar issues.

The correct option is (a) CLASS student{public:int marks;}s;class stream{int total;}; class topper:public student, public stream{};

The best explanation: Class topper is getting DERIVED from 2 other CLASSES and hence it is multiple INHERITANCE. Topper inherits class stream and class student PUBLICLY and hence can use its features. If only few classes are defined, there we are not even using inheritance (as in option class student{ }; class stream{ }; class topper{ };).

Right answer is (b) A class INHERITING a base class

Easiest explanation - A class inheriting a base class DEFINES single level inheritance. Inheriting an already DERIVED class makes it MULTILEVEL inheritance. And if base class is inherited by 2 other classes, it is multiple inheritance.

Right choice is (a) 4

The explanation: There are BASICALLY 4 types of inheritance provided in OOP, namely, single level, MULTILEVEL, multiple and HIERARCHICAL inheritance. We can add ONE more type as HYBRID inheritance but that is actually the combination any types of inheritance from the 4 basic ones.

Correct choice is (d) Using the data and FUNCTIONS into derived segment

To explain I would say: It can only be indicated by using the data and functions that we USE in derived class, being PROVIDED by parent class. COPYING code is nowhere similar to this concept, also using the code already written is same as copying. Using already defined functions is not inheritance as we are not adding any of our own features.