Question

As the classes use the concept of data abstraction, they are known as:

1. Abstract data types
2. Abstract object types
3. Null object types
4. Null data types

10. A destructor is defined as following

1. className ~( ) { }
2. className ~ { }
3. :: className ( ) { }
4. ~className ( ) { }

Answer 1

Q9) answer is option A

option A: data abstraction means providing only the essential details for the view and hiding behind the background details.

in C++ classes are providing great level of data abstraction.

Abstract data type is the type or class of objects whose implementation details are hidden, the set of operations to be performed are only explained. That is all background details are abstracted.

option B: there is no concept called abstract object type

option C: in javascript type of null is object, but in other languages null means nothing

option D: data type for null is not having any meaning because null means 0 it can be considered under many datatypes like, integer, float etc.

--------------------------------------------------------------------------------------------------------------

Q10) answer is option D

option A: is wrong definition of destructor

option B:is wrong definition of destructor

option C:is wrong definition of destructor

option D:

a destructor is a special class function

its used to destroy the object when this object goes out of scope.

when the object goes out of scope, the compiler automatically calls the destructor.

defining a constructor:

• class name itself is used for the constructor
• while defing a constructor, the classname is prefixed with a tilde (~) symbol.
• as, ~ classname () { }