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The correct option is (d) VIRTUAL FUNCTION

Easy explanation - Virtual Functions can be defined in any class USING the keyword virtual. All the classes which inherit the class containing the virtual function, DEFINE the virtual function as REQUIRED. Redefining the function on all the derived classes according to class and use represents polymorphism.

The correct answer is (d) The LANGUAGE must follow all the RULES of OOP

Easiest explanation - The language must follow all the rules of OOP to be CALLED a PURELY OOP language. Even if a single OOP feature is not followed, then it’s known to be a PARTIALLY OOP language.

Right option is (a) OPERATOR Overloading

The BEST I can EXPLAIN: The feature is operator overloading. There is not a feature named operator OVERRIDING SPECIFICALLY. Function overloading and overriding doesn’t give addition function to any operator.

The correct option is (a) True

Explanation: Exception handling is a feature of OOP as it includes classes CONCEPT in most of the CASES. Also it may come handy while using INHERITANCE.

Correct ANSWER is (B) Function overriding

Easy explanation - Function overriding doesn’t illustrate polymorphism because the FUNCTIONS are actually different and theirs scopes are different. Function and operator overloading illustrate proper polymorphism. VIRTUAL functions show polymorphism because all the CLASSES which inherit virtual function, define the same function in different ways.

Right choice is (d) Ada

Explanation: Ada is the LANGUAGE which supports the CONCEPT of classes but doesn’t SUPPORT the polymorphism feature. It is an object-based PROGRAMMING language. NOTE that it’s not an OOP language.

Right CHOICE is (a) Always TRUE for any programming language

Explanation: It is always true as we have the facility of private and PROTECTED access specifiers. Also, only the public and global data are available GLOBALLY or else the program should have proper permission to access the private data.

Correct choice is (c) Polymorphism

Easy explanation - The feature defined in QUESTION defines polymorphism features. Here the DIFFERENT objects are capable of responding to the same MESSAGE in different ways, hence polymorphism.

Correct answer is (b) Function with highest priority in compiler

The explanation: Function with highest priority is called. Here, it’s not about the thread SCHEDULING in CPU, but it focuses on whether the function in local SCOPE is PRESENT or not, or if scope resolution is used in some way, or if the function matches the argument signature. So all these things DEFINE which function has the highest priority to be called in runtime. Local function could be one of the answer but we can’t say if someone have used POINTER to another function or same function name.

The correct choice is (a) STATIC member FUNCTIONS

To EXPLAIN I would say: Static member functions are not property of any object. Hence it can’t be CONSIDERED for overloading/overriding. For polymorphism, function must be property of object, not only of class.

The correct ANSWER is (c) Overloading <<

Easiest explanation - Only insertion operator can be OVERLOADED among all the given options. And the POLYMORPHISM can be ILLUSTRATED here only if any of these is applicable of being overloaded. Overloading is type of polymorphism.

Correct option is (c) All the derived CLASSES must implement the undefined functions

The best EXPLANATION: The undefined functions must be defined is a problem, because one may need to implement few undefined functions from abstract class, but he will have to DEFINE each of the functions DECLARED in abstract class. Being USELESS task, it is a problem sometimes.

The correct choice is (a) True

Explanation: It is possible to implement polymorphism in C LANGUAGE, even though it doesn’t support class. We can use structures and then declare pointers which in turn points to some function. In this way we simulate the functions LIKE MEMBER functions but not exactly member function. Now we can overload these functions, HENCE implementing polymorphism in C language.

The correct ANSWER is (d) Increases overhead of FUNCTION definition always

For EXPLANATION: It never increases function definition overhead, one way or another if you don’t use polymorphism, you will use the definition in some other way, so it actually HELPS to write efficient codes.

The correct choice is (d) Either FUNCTION overloading or operator overloading because POLYMORPHISM can be applied only once in a program

The best explanation: Both of them are using polymorphism. It is not NECESSARY that polymorphism can be used only once in APROGRAM, it can be used anywhere, any number of times in a single program.

Right choice is (d) It is a way of COMBINING various data members and member functions that OPERATE on those data members into a single UNIT

Best explanation: It is a way of combining both data members and member functions, which operate on those data members, into a single unit. We call it a class in OOP generally. This feature have helped us modify the structures used in C LANGUAGE to be UPGRADED into class in C++ and other languages.

Correct answer is (a) Create PUBLIC member functions to access those data members

Best EXPLANATION: We can define public member functions to access those private data members and get their value for use or ALTERATION. They can’t be ACCESSED directly but is possible to be access using member functions. This is done to ENSURE that the private data doesn’t get modified accidentally.

The correct option is (c) class student{INT a; PUBLIC: void disp(){ cout<
The explanation is: It is the class which uses both the data members and member functions being declared inside a single UNIT. Only data members can be there in structures also. And the encapsulation can only be ILLUSTRATED if some data/operations are associated within class.

Correct option is (b) Data member’s data TYPE can be changed without changing any other code

To explain I WOULD say: Data member’s data type can be changed without changing any further code. All the members using that data can continue in the same way without any modification. Member FUNCTIONS can NEVER change the data type of same class data members.

Right option is (B) ABSTRACTION

Easiest explanation - Data abstraction can be achieved by using ENCAPSULATION. We can hide the OPERATION and structure of actual program from the user and can show only required information by the user.

The correct answer is (a) The data which is prone to CHANGE is near FUTURE

To explain: The data prone to change in near future is usually encapsulated so that it doesn’t get changed ACCIDENTALLY. We ENCAPSULATE the data to hide the critical working of program from outside world.

The correct answer is (a) USING Access Specifiers

The explanation: Using access specifiers we can ACHIEVE encapsulation. Using this we can in turn IMPLEMENT data abstraction. It’s not necessary that we only use PRIVATE access.

Correct answer is (b) Global variables

Explanation: Global variables almost ALWAYS violates the principles of encapsulation. Encapsulation says the data should be ACCESSED only by required set of elements. But global variable is accessible everywhere, also it is most prone to changes. It doesn’t HIDE the internal WORKING of PROGRAM.

Correct choice is (d) Using any kind of pointer/array address in passing to ANOTHER function

To explain I would say: If we USE any kind of array or pointer as data member which should not be changed, but in some case its address is passed to some other function or similar VARIABLE. There are chances to MODIFY its whole data easily. Hence Against encapsulation.

Correct option is (B) False

Easy explanation - False, because we can’t call these STRUCTURES if MEMBER functions are involved, it must be called class. Also, it is not just about adding functions, it’s about BINDING DATA and functions together.

Right choice is (b) ENSURED to some extent

For EXPLANATION: The encapsulation can only ensure DATA security to some extent. If POINTER and ADDRESSES are misused, it may violate encapsulation. Use of global variables also makes the program vulnerable, hence we can’t say that encapsulation gives pure security.

Correct option is (d) Hiding the implementation and showing only the features

The BEST I can explain: It includes hiding the implementation part and showing only the required data and features to the user. It is done to hide the implementation COMPLEXITY and details from the user. And to provide a GOOD INTERFACE in programming.

The correct ANSWER is (a) Make the programming EASY

The best I can explain: It can make programming easy. The programming need not KNOW how the inbuilt functions are WORKING but can use those complex functions directly in the program. It doesn’t provide more number of features or better features.

The CORRECT option is (c) Real

The EXPLANATION: OBJECT is real abstraction because it ACTUALLY contains those features of class. It is the implementation of overview GIVEN by class. Hence the class is logical abstraction and its object is real.

The correct option is (b) LOGICAL

The BEST explanation: Class is logical abstraction because it provides a logical STRUCTURE for all of its objects. It gives an OVERVIEW of the features of an object.

The correct choice is (c) IDEALIZED interface

The best explanation: It is to idealize the interface. In this way the programmer can use the programming features more efficiently and can code better. It can’t INCREASE the program COMPLEXITY, as the FEATURE itself is made to HIDE it.

The correct option is (B) OBJECT

The EXPLANATION is: Object can be viewed as abstraction of data and code. It uses data members and their functioning as data abstraction. Code abstraction as USE of object of inbuilt class.

Correct answer is (c) Use abstraction whenever possible to avoid duplication

Best explanation: Abstraction principle INCLUDES use of abstraction to avoid duplication (usually of code). It this way the PROGRAM doesn’t CONTAIN any redundant functions and MAKE the program efficient.

The CORRECT answer is (B) False

To explain I WOULD SAY: Higher the level of abstraction, lower are the details. The best way to understand this is to CONSIDER a whole system that is highest level of abstraction as it hides everything inside. And next lower level would contain few of the computer components and so on.

The correct OPTION is (a) BINDING and HIDING respectively

Best explanation: Abstraction is hiding the complex code. For example, we directly use cout object in C++ but we don’t know how is it actually implemented. Encapsulation is data binding, as in, we TRY to combine a SIMILAR type of data and functions together.

The correct choice is (d) PHONE

Explanation: Phone as a whole have the highest level of abstraction. This is because the phone being a single unit represents the whole SYSTEM. Whereas motherboard, DISPLAY and CAMERA are its components.

Correct answer is (c) Using PUBLIC member functions to access and manipulate the data members

The explanation is: It is the concept of hiding program complexity and actual working in background. Hence USE of public member functions ILLUSTRATES ABSTRACTION here.

Right choice is (a) Abstraction is called a stream and device is called a file

Explanation: Abstraction is called stream to provide a LEVEL of complexity hiding, for how the files operations are actually DONE. Actual devices are called file because in ONE WAY or ANOTHER, those can be considered as single entity and there is nothing hidden.

Correct answer is (d) External level

Explanation: Abstraction is generally DIVIDED into 3 different levels, namely, logical, PHYSICAL and view level. External level is not defined in TERMS of abstraction.