Question 1

What member functions do you need to allow the compiler to perform automatic type conversions from a type different than the class to the class?

Accepted Answer

To allow the compiler to perform automatic type conversions from a type different than the class to the class, we need to provide overloaded constructors that accept the different type(s). This allows the compiler to implicitly convert the input type to the class type using the provided constructor.

Question 2

Given the following function declaration,
Friend void displayconst myClass& object);
Which is the correct header for the definition of the function?

Accepted Answer

The correct header for the definition of a friend function is the same as its declaration inside the class, but without the 'friend' keyword. Since the function is not a member of the class (indicated by the absence of myClass:: in the function name), option B is correct.

Question 3

The destructor for a class is called

Accepted Answer

The destructor is automatically called when the object of the class goes out of scope, meaning when it is no longer in use or accessible. It is not called explicitly from the main program or when the class is instantiated. It may also be called at the end of the main function, but this is not the only time it is called.

Question 4

Which of the following statements are true?

Accepted Answer

A) A dynamic array can have a base type which is a class or a struct. This is true, as dynamic arrays can be created with any base type.
B) A class or a struct may have a member which is a dynamic array. This is also true, as classes and structs can contain members of any type, including dynamic arrays.

Question 5

In an overloaded insertion or extraction operator, which object should be the first parameter, the stream or the object of the class?

Accepted Answer

The stream should always be the first parameter in overloaded insertion or extraction operator because the insertion or extraction operation is always called on the stream object.

Question 6

If obj1 and obj2 are both objects of a class that uses dynamic memory allocation, but the class does not have an assignment operator, what happens if you execute the following code?
Obj1=obj2;

Accepted Answer

When you assign one object to another without a user-defined assignment operator in C++, the default assignment operator is used. This operator performs a shallow copy, meaning it copies the values of the members of obj2 to obj1 directly, including the pointers to dynamically allocated memory. This does not create independent copies of the dynamic memory; both objects end up pointing to the same memory locations.

Question 7

Which of the following are not correct?

Accepted Answer

The destructor of a class is not a void function; it has no return type. A and C are correct: the destructor is named with a tilde preceding the name of the class, and it is not a member of the class. B is incorrect; the destructor is called when an object of the class goes out of scope. Therefore, the correct choice is D, which is the only option that is not correct.

Question 8

Which of the following statements are true?

Accepted Answer

A) Yes, array elements may be user-defined types such as structs or classes.
B) Yes, if a function is expecting a variable of the base type of the array, then you can pass an element of the array to the function. 
So, both statements are true making the correct answer C.

Question 9

Which of the following are valid declarations for an assignment operator for a class named myClass?

Accepted Answer

The answer of Which of the following are valid declarations...

Question 10

The copy constructor for a class is called

Accepted Answer

The copy constructor is invoked in all these scenarios: when an object is passed by value to a function, when an object is initialized by another object, and when a function returns an object of the class, potentially invoking copy elision optimization.

Question 11

Which of the following operators can not be overloaded?

Accepted Answer

The dot operator (.) is used for member access and cannot be overloaded. The other operators listed can be overloaded.

Question 12

Given the following class and array declaration, how would you print out the age of the 10^th person in the array? Class personClass { Public: Void setAgeint newAge); Void setGender char newGender); Void setSalaryfloat newSalary); Int getAge); Char getGender); Float getSalary); Private: Int age; Char gender; Float salary; }; PersonClass people[100];

Accepted Answer

To access the age of a person object in the array, we need to use the getAge function as it is a private variable of the class and cannot be accessed directly. The correct syntax for calling the function is nameOfObject.getAge(). Option A and B are incorrect because they do not specify which information from the object to print. Option C is incorrect because it is attempting to access a private variable directly.

Question 13

Why are the extraction and insertion operators always implemented as friends of the class rather than as members of the class?

Accepted Answer

The extraction (>>) and insertion (<<) operators are implemented as friends rather than members because the first parameter for these operators must be the stream object (std::istream for extraction, std::ostream for insertion), not the object of the class they are meant to work with. This allows for the correct chaining of these operators in expressions.

Question 14

Which of the following function declarations would be correct to overload the multiply operator for the Rational numbers class?

Accepted Answer

To overload the multiply operator for the Rational numbers class, we need to define a friend function that takes two Rational number objects as arguments and returns a Rational number object. The function should have the signature `friend Rational operator*(const Rational& left, const Rational& right)`.

Option A is incorrect because the function should not be declared as a friend in the function signature.

Option B is incorrect because the function should be defined as a friend function outside the class definition.

Option D is incorrect because the function should not have the `const` qualifier in the function signature.

Therefore, option C is the correct choice.

Question 15

What happens when you define a class that used dynamic memory allocation and define a destructor but no copy constructor?

Accepted Answer

The answer of What happens when you define a class...

Question 16

When a dynamic array with a class for a base type is declared, which constructor is called?

Accepted Answer

When a dynamic array is declared, the default constructor is called to initialize the elements of the array.

Quiz 11: Friends, Overloaded Operators, and Arrays in Classes

What member functions do you need to allow the compiler to perform automatic type conversions from a type different than the class to the class?

Given the following function declaration, Friend void displayconst myClass& object) ; Which is the correct header for the definition of the function?

The destructor for a class is called

Which of the following statements are true?

In an overloaded insertion or extraction operator, which object should be the first parameter, the stream or the object of the class?

If obj1 and obj2 are both objects of a class that uses dynamic memory allocation, but the class does not have an assignment operator, what happens if you execute the following code? Obj1=obj2;

Which of the following are not correct?

Which of the following statements are true?

Which of the following are valid declarations for an assignment operator for a class named myClass?

The copy constructor for a class is called

Which of the following operators can not be overloaded?

Why are the extraction and insertion operators always implemented as friends of the class rather than as members of the class?

Which of the following function declarations would be correct to overload the multiply operator for the Rational numbers class?

What happens when you define a class that used dynamic memory allocation and define a destructor but no copy constructor?

When a dynamic array with a class for a base type is declared, which constructor is called?