OOP6 Polymorphism

Question 1

What is function overloading?

Answer 1

The use of the same name for different functions, distinguished by their parameter lists

Question 2

What is a generic algorithm?

Answer 2

An algorithm where a series of steps or operations are defined but the data type of the items being manipulated are not.

Question 3

What is operator overloading?

Answer 3

Allows to redefine the standard C++ operators

Question 4

What does typedef keyword do?

Answer 4

Defines a data type with a new user generated identifier

Question 5

What is a generic data type?

Answer 5

A type for which the operations are defined but the data being manipulated is not

Question 6

What is a class template?

Answer 6

A construct whereby the compiler may generate multiple versions of a class through parameterised data types

Question 7

How to define a class template?

Answer 7

template <parameter>
Class Definition {};</parameter>

Question 8

What is a template parameter?

Answer 8

A parameter that is used in the template definition

Question 9

What is required type of a parameter template parameter?

Answer 9

class/typename

Question 10

How to instantiate a new class from a template?

Answer 10

template<class>
class GList {…};
…
GList<int> intList;</int></class>

Question 11

Newly instantiated classes from templates are called?

Answer 11

Generated classes, template classes

Question 12

How can the relationship between a class template and template classes be defined?

Answer 12

A template class is a specialisation of the class template

Question 13

What is a function template?

Answer 13

A construct that allows the compiler to generate multiple versions of a function according to allowing parameterised data types

Question 14

How to define a function template?

Answer 14

template<class>
void GList<ItemType>::foo(ItemType i)
{…}</ItemType></class>

Question 15

Template functions should use const reference parameters. Why?

Answer 15

Because they are much more efficient for memory

Question 16

Const reference parameters for template functions ensure what?

Answer 16

That the object being oassed by const reference, will only allow its const functions (observer/accessor functions) to execute within the scope of this function

Question 17

How to instantiate a template function?

Answer 17

template<typename>
void Foo(ItemType i)
{…}
…
Foo<int>(i);</int></typename>

Question 18

The template argument of a function template is optional. True or false?

Answer 18

True

Question 19

How does the compiler know which template function to call with no template argument list?

Answer 19

It examines the type of the passed argument

Question 20

How to define an overloaded operator function?

Answer 20

returnType operator<(const itemType& comparatorItem) const
{…}

Question 21

How do overloaded operators compare two variables?

Answer 21

The first operand is the one on the left, the passed parameter is the second operand

Question 22

What operators cannot be overloaded?

Answer 22

sizeof(), ., ::, ?:

Question 23

How to overload a unary operator?

Answer 23

dataType operator-() const;

Question 24

What does the this keyword do?

Answer 24

This contains a pointer to whichever object that the function where this is called belongs to

Question 25

How can you refer to the actual object itself inside an object?

Answer 25

Dereference the this keyword, like so: *this

Question 26

What keyword is used for a function to prevent it from being overridden?

Answer 26

Final

Question 27

Early and late binding are other words for:

Answer 27

Static and dynamic binding

Question 28

Which are the only two types of member functions that can use dynamic binding/virtual keyword, and what cannot?

Answer 28

Ordinary members, destructors, NOT friend, static or constructors

Question 29

How is a pure virtual function defined?

Answer 29

It has no body, used in base class but must be overridden in the derived class, ended with = 0;,

Question 30

Destructor functions must be ___ if the object will be manipulated polymorphically

Answer 30

Virtual

Question 31

Why must polymorphic classes have virtual destructors?

Answer 31

The base class destructor might be called instead, producing undefined behaviour

Question 32

Pointer variables for base classes can accept pointers for which types?

Answer 32

The base class and any derived class