Question

Consider the following statements: class temporary { public: void set(string, double, double); void print(); double manipulate(); void get(string&, double&, double&); void setDescription(string); void setFirst(double); void setSecond(double); string getDescription() const; double getFirst()const; double getSecond()const; temporary(string = "", double = 0.0, double = 0.0); private: string description; double first; double second; }; a. How many members does class temporary have? b. How many private members does class temporary have? c. How many constructors does class temporary have? Can this constructor be used to initialize an object without specifying any parameters? If yes, then illustrate with an example; otherwise, explain why it cannot be used to initialize an object witout specifying any parameters.

Short answer

Class temporary has 14 members, 3 private members, and 1 constructor which can be used without parameters.

Step-by-step solution

Identify the Total Members

A class member can be a data member or a member function. In the class `temporary`, identify the total members by counting both the data members and member functions. - Data Members: `description`, `first`, and `second` - Member Functions: `set`, `print`, `manipulate`, `get`, `setDescription`, `setFirst`, `setSecond`, `getDescription`, `getFirst`, `getSecond`, and the constructor `temporary`. So, the total number of class members is 3 (data members) + 11 (member functions) = 14.

Count the Private Members

Private members are explicitly listed under the `private` access specifier. In class `temporary`, the private data members are `description`, `first`, and `second`. There are no private member functions mentioned explicitly related to these specific data members. Thus, the number of private members is 3.

Identify and Describe the Constructors

A constructor is a special type of member function used to initialize objects. The class `temporary` has one constructor definition as `temporary(string = "", double = 0.0, double = 0.0)`. This constructor can be called with default parameters because each parameter has a default value specified. Since all parameters have default values, this constructor can be used to initialize an object without specifying any parameters.

Provide an Example for Default Constructor Usage

Illustrate the use of the default constructor without parameters. ```cpp // Creating an object of class temporary without passing any arguments // This will invoke the constructor with default parameters temporary tempObject; ```

Key concepts

Data Members

Data members are variables that hold the data specific to a class in C++. They define the properties of objects created from the class. In the class `temporary`, the data members include:

• description: A string storing a descriptive text.
• first: A double representing the first numerical value.
• second: Another double holding the second numerical value.

These members are crucial as they store the state of an object. They are declared in the private section of the class to protect them from unintended modifications from outside the class itself. Access to these data members is typically managed through member functions.

Member Functions

Member functions in C++ are designed to manipulate data members and define class behaviors. They allow interaction with class data safely and effectively. In the `temporary` class, member functions include:

• set(): Assigns values to the data members.
• print(): Outputs the details of the object's state.
• manipulate(): Performs calculations or modifications involving data members.
• get(): Retrieves current values of the data members.
• setDescription(), setFirst(), setSecond(): These set specific data members.
• getDescription(), getFirst(), getSecond(): Retrieve the values of specific data members.
• The temporary constructor initializes objects.

These functions can modify or provide access to the data while maintaining the integrity and security of the internal state.

Default Constructor

A default constructor is a special member function that initializes objects of a class, setting up initial values for data members. It is called automatically when an object is instantiated with no initial arguments. In the `temporary` class, the constructor is defined as:\[\text{temporary(string = "", double = 0.0, double = 0.0)}\]Each parameter has a default value, allowing the constructor to initialize an object without needing any explicit arguments. The use of default values makes it highly versatile. For instance, creating an instance of `temporary` can be done simply by writing:```cpptemporary tempObject;```This line creates a `temporary` object with `description` set to an empty string, and both `first` and `second` initialized to 0.0. This facilitates quick initialization where specific values aren't necessary or yet available.

Access Specifiers

Access specifiers in C++ control how class members are accessed. They determine the visibility and accessibility of data members and member functions. In our `temporary` class, there are two primary access specifiers:

• public: Members declared under it are accessible from outside the class. For the `temporary` class, all member functions are public, allowing them to manipulate or retrieve data.
• private: Limits access solely within the class itself. Only member functions or friends of the class can access private members. In `temporary`, description, first, and second are private to prevent unauthorized external modification.

Through careful use of these specifiers, a class can encapsulate its data and ensure that its internal state remains controlled and predictable. This separation is a cornerstone of object-oriented programming, promoting data integrity and security.