Question

Select all that are true regarding abstract classes.

A - They express all the properties and behaviors common to their subclasses.

B - Calling the constructor will result in a compile time error.

C - Contain implemented methods.

D - Abstract classes can be used to create objects.

Answer 1

Correct Answer: A, C

Explanation:

Abstract Class:

An abstract class is a class that has at least one pure virtual function and this class never instantiated directly. This class is mostly used to define the base class in the class hierarchy.

Constructor:

In object-oriented programming, a constructor is a special method of the class that has the same name as the class name and it initializes the data member at object creation time.

The option 'A' is correct because an abstract class expresses the common properties of the subclasses.

The option 'B' is incorrect because a constructor is used to initialize the object automatically but an abstract class can't be used to create an object.

Option 'C' is correct because an abstract class can contain implemented methods.

Option 'D' is incorrect because an abstract class can't be used to create objects.

So, the option 'A' and 'C' are correct.