Question 1

A default constructor:

Accepted Answer

A default constructor is automatically generated by the compiler if no constructors are explicitly defined by the programmer, and it does not necessarily require any arguments.

Question 2

Assuming the following constructor is provided for class Time explicit Time(int = 0, int = 0, int = 0);
Which of the following is not a valid way to initialize a Time object?

Accepted Answer

All options A, B, and C are valid ways to initialize a Time object given the constructor definition allows for 0 to 3 integer arguments, with default values of 0.

Question 3

A class's functions can throw exceptions, such as __________to indicate invalid data.

Accepted Answer

"invalid_argument" is a standard exception in C++ that is typically used to indicate that a function has been passed an invalid argument. It is a more specific and accurate description compared to the other options.

Question 4

Member access specifiers (public and private) can appear:

Accepted Answer

Member access specifiers in C++ (public and private) can appear in any order within a class definition and can be used multiple times to change the access level of the members that follow.

Question 5

Member function definitions:

Accepted Answer

Member function definitions can be written inside the definition of their class without the scope resolution operator. However, if they are defined outside of the class definition, the scope resolution operator is required to specify which class the function belongs to.

Question 6

Which of the following statements is false (assume we're referring to class Time)?

Accepted Answer

The answer of Which of the following statements is false...

Question 7

The type of function a client would use to check the balance of a bank account would be:

Accepted Answer

An access function is designed to retrieve data from a system or object, allowing a client to access information about the bank account, such as its current balance.

Question 8

Parameterized stream manipulator setfill specifies the fill character that's displayed when an output is displayed in a field wider than the number of characters or digits in the output. The effect of setfill applies:

Accepted Answer

The effect of setfill applies until explicitly set to a different setting.

Question 9

Given the class definition: class CreateDestroy
{
Public:
CreateDestroy() {cout << "constructor called, ";}
~CreateDestroy() {cout << "destructor called, ";}
};
What will the following program output?
Int main()
{
For (int i = 1; i <= 2; ++i) {
CreateDestroy cd;
}
Return 0;
}

Accepted Answer

In the given program, the `CreateDestroy` object `cd` is created and destroyed within each iteration of the for loop. This results in the constructor being called when the object is created and the destructor being called when the object goes out of scope at the end of each iteration, producing the output "constructor called, destructor called," twice.

Question 10

Which of the following is not true of a constructor and destructor of the same class?

Accepted Answer

Explanation: Constructors in C++ can have default arguments, allowing them to be called with fewer arguments than there are parameters. This is not true for destructors, which cannot take any arguments and therefore cannot have default arguments. Destructors are defined without parameters and are used to clean up resources when an object's lifetime ends.

Question 11

A class-scope variable hidden by a block-scope variable can be accessed by preceding the variable name with the class name followed by:

Accepted Answer

The scope resolution operator (::) can be used to access global or class scope variables that are hidden by local variables.

Question 12

Variables defined inside a member function of a class have:

Accepted Answer

Variables defined inside a member function of a class have block scope, meaning they can only be accessed within the curly braces of the function. They do not have class or file scope. The binary scope resolution operator (::) is only used to access variables or functions that have been defined outside of the member function, such as class members or global variables.

Question 13

Which of the following statements is false (ssume we're referring to class Time)?

Accepted Answer

The answer of Which of the following statements is false...

Question 14

Given the class definition: class CreateDestroy
{
Public:
CreateDestroy() {cout << "constructor called, ";}
~CreateDestroy() {cout << "destructor called, ";}
};
What will the following program output?
Int main()
{
CreateDestroy c1;
CreateDestroy c2;
Return 0;
}

Accepted Answer

When the program is run, it creates two objects of the CreateDestroy class: c1 and c2. For each object, the constructor is called upon creation and the object is initialized. Therefore, "constructor called" is printed twice. When the program ends and the objects are destroyed, the destructor is called for each object. Therefore, "destructor called" is printed twice. Hence, the correct output is: "constructor called, constructor called, destructor called, destructor called" which is option D.

Question 15

Every object of the same class:

Accepted Answer

Every object of a class gets its own copy of member variables, allowing each object to maintain its own state. Member functions, however, are shared among all objects of the class; they do not get individual copies per object.

Question 16

Which of the following statements is false?

Accepted Answer

In C++, you can call another constructor in the same class using the syntax known as the constructor chaining or delegated constructor.

Question 17

Which of the following is not true of a destructor?

Accepted Answer

Destructors are responsible for performing cleanup tasks and are called before the system reclaims the object's memory, but they do not themselves release the object's memory. Memory management, such as deallocating memory, is handled by the garbage collector or the programmer, depending on the programming language.

Question 18

Which of the following preprocessor directives does not constitute part of the preprocessor wrapper?

Accepted Answer

#include is a preprocessor directive used to include files in the program, but it is not part of the preprocessor wrapper. The preprocessor wrapper typically involves conditional compilation directives like #ifndef, #define, and #endif to prevent double inclusion of header files.

Question 19

If a member function of a class already provides all or part of the functionality required by a constructor or another member function then:

Accepted Answer

The best choice is to call that member function from the constructor or member function that requires the functionality. Copying and pasting code is not recommended as it violates DRY (Don't Repeat Yourself) principle and can lead to errors and maintenance issues. If the member function already provides the required functionality, then it should not be considered unnecessary. Similarly, if the constructor or member function is required for the class, it should not be considered unnecessary.

Question 20

Utility functions:

Accepted Answer

Utility functions are private member functions that support the operations of the other member functions within a class. They are not intended to be used by clients of the class and are not part of the class's interface, nor are they constructors.

Quiz 9: Classes: a Deeper Look; Throwing Exceptions