Question

Suppose that you have the following definitions: struct timeType struct tourType { { int hr; string cityName; double min; int distance; int sec; timeType travelTime; }; }; a. Declare the variable destination of type tourType. b. Write C++ statements to store the following data in destination: cityName—Chicago, distance—550 miles, travelTime—9 hours and 30 minutes. c. Write the definition of a function to output the data stored in a variable of type tourType. d. Write the definition of a value-returning function that inputs data into a variable of type tourType. e. Write the definition of a void function with a reference parameter of type tourType to input data in a variable of type tourType.

Short answer

Declare a `tourType` variable, populate it, and define input/output functions.

Step-by-step solution

Declare the Variable

First, we need to declare a variable of type `tourType` using the provided structure. ```cpp tourType destination; ```

Store Data in Variable

Next, we will store the given information into the variable `destination`. We break it into city name, distance, and travel time as follows: ```cpp destination.cityName = "Chicago"; destination.distance = 550; destination.travelTime.hr = 9; destination.travelTime.min = 30; destination.travelTime.sec = 0; // Assuming seconds are zero since not provided. ```

Define Input Function for tourType

Now, we define a value-returning function that inputs data into a variable of type `tourType`: ```cpp tourType inputTourType() { tourType temp; cout << "Enter city name: "; cin >> temp.cityName; cout << "Enter distance: "; cin >> temp.distance; cout << "Enter travel time (hours minutes seconds): "; cin >> temp.travelTime.hr >> temp.travelTime.min >> temp.travelTime.sec; return temp; } ```

Define Output Function

Next, we write the definition of a function to output the data stored in a variable of type `tourType`: ```cpp void printTourType(const tourType& tour) { cout << "City Name: " << tour.cityName << endl; cout << "Distance: " << tour.distance << " miles" << endl; cout << "Travel Time: " << tour.travelTime.hr << " hours, " << tour.travelTime.min << " minutes, " << tour.travelTime.sec << " seconds" << endl; } ```

Define Void Function with Reference Parameter

Finally, define a void function that uses a reference parameter to input data: ```cpp void inputTourType(tourType& tour) { cout << "Enter city name: "; cin >> tour.cityName; cout << "Enter distance: "; cin >> tour.distance; cout << "Enter travel time (hours minutes seconds): "; cin >> tour.travelTime.hr >> tour.travelTime.min >> tour.travelTime.sec; } ```

Key concepts

C++ Data Types

In C++ programming, understanding data types is fundamental. Each piece of data you use has a specific type that defines what value it can hold and how it can be manipulated. Some common data types include:

• int: Used for whole numbers, such as -1, 0, 23.
• double: Represents floating-point numbers, including fractions and decimals, like 3.14 or -268.75.
• string: Utilized for sequences of characters or text, like "hello" or "city name".

These data types allow you to perform mathematical operations, store information, and handle text. By utilizing different data types, you can more efficiently use memory in your programs and avoid errors. For instance, using an int when you need to store perfectly rounded numbers or a double when working with precise calculations.

Struct Data Structure

The struct keyword in C++ is used to create a data structure that groups multiple variables into a single unit. This feature allows you to model complex objects that contain various attributes. In our example, we have two structures:

• timeType: This struct holds time-related data with attributes for hours, minutes, and seconds. Each attribute has its specific data type: int for hours and double for minutes and seconds.
• tourType: Contains a city's name, its distance from another point, and a travel time, which itself is a timeType struct. This demonstrates nesting one structure within another, enabling detailed data organization.

Using structs makes your code more readable, manageable, and organized since it bundles related data together. It enhances code reusability and allows object-oriented principles to be applied in C++ effectively.

Function Definition

When defining functions in C++, you specify a block of code designed to perform a task. Functions are important because they help break your program into smaller, manageable parts. Here's a rundown of the function concepts relevant to our exercise:

• Function Declaration: This tells the compiler about the function's name, return type, and parameters. It doesn't contain the actual function code.
• Function Definition: This is where you specify the function's actions. It includes a body that executes when the function is called.

For example, we use a value-returning function, inputTourType(), that prompts the user to input details about a tour and then returns a tourType object. Additionally, a void function like printTourType() simply outputs data without returning a value. Functions enhance code clarity, promote reuse, and reduce redundancy.

Pass by Reference

In C++, passing by reference involves passing the memory address of a variable rather than its actual value. This approach has several advantages:

• No Copying: Since no copy of the variable is made, it saves memory and time, especially with large data structures.
• Direct Modification: Changes made inside the function affect the original variable, allowing you to directly manipulate an object's properties.

In the exercise, we defined a void function with a reference parameter using tourType& tour. This allows the function to modify the caller's data directly. By using the "&" symbol, we've enabled efficient parameter transmission, ensuring the function works on the actual data rather than a duplicate. Pass by reference is crucial when working with large structures like our tourType, making operations efficient and streamlined.