Question

Use the following car structure declaration to answer. struct Car string make, model ; int year ; double cost ; / / Constructors \(\operatorname{car}()\) \(\\{\text { make }=\text { model }=" " ; \text { year }=\operatorname{cost}=0 ; \\}\) Car (string mk, string md, int yr, double \(\\{\text { make }=\mathrm{mk} ; \text { model }=\mathrm{md} ; \text { year }=\mathrm{yr} ; \text { cost }=\mathrm{c} ;\\}\) Define an array named forsale that holds 35 car structures. Initialize the first three elements with the following data: $$\begin{array}{llcc} \text { Make } & \text { Model } & \text { Year } & \text { cost } \\ \text { Ford } & \text { Taurus } & 2006 & \$ 21,000 \\ \text { Honda } & \text { Accord } & 2004 & \$ 11,000 \\ \text { Jeep } & \text { Wrangler } & 2007 & \$ 24,000 \end{array}$$

Short answer

Answer: The "forsale" array can hold 35 car structures. The initial values of the first three elements are: 1. Element 0: A 2006 Ford Taurus with a cost of $21,000. 2. Element 1: A 2004 Honda Accord with a cost of $11,000. 3. Element 2: A 2007 Jeep Wrangler with a cost of $24,000.

Step-by-step solution

Declare the Car structure and constructors

The given Car structure and its constructors are: ```cpp struct Car { string make, model; int year; double cost; // Constructors Car() { make = model = ""; year = cost = 0; } Car(string mk, string md, int yr, double c) { make = mk; model = md; year = yr; cost = c; } }; ``` We have declared the structure "Car" with the necessary variables and constructors.

Create an array of 35 Car structures

Declare an array that can store 35 Car structures and name it "forsale": ```cpp Car forsale[35]; ```

Initialize the first three elements with given data

Use the given data to initialize the first three elements of the "forsale" array: ```cpp forsale[0] = Car("Ford", "Taurus", 2006, 21000); forsale[1] = Car("Honda", "Accord", 2004, 11000); forsale[2] = Car("Jeep", "Wrangler", 2007, 24000); ``` Now, the "forsale" array has been declared with 35 car structures and the first three elements have been initialized with the provided data.

Key concepts

C++ Data Structures

Data structures are fundamental concepts in programming that store and manage data efficiently. In C++, a structure, often referred to as a 'struct', is a user-defined composite data type that allows us to combine items of possibly different types into a single type.

Data structures are essential for organizing data, making it easier to process and manipulate. They can represent real-world objects with various attributes. For example, consider a 'Car' struct that could include characteristics like make, model, year, and cost. C++ structs are particularly useful in situations where logic requires a complex object that contains multiple attributes.

Structs in C++ are defined using the 'struct' keyword, followed by the structure name and the block of member variables. They are versatile and can include other structs, arrays, and even functions, such as constructors. Constructors within structs are special member functions that are called when new objects of that structure are created, ensuring that they are properly initialized.

C++ Constructors

Constructors in C++ play a vital role in initializing newly created objects. They are special member functions with the same name as the struct or class they are initializing. Constructors can be overloaded, meaning you can have multiple constructors with different parameters.

In the context of the 'Car' struct, there are two constructors defined. The first constructor is the default constructor, without any parameters, which sets the member variables to default values. The second constructor takes parameters for each of the member variables (make, model, year, and cost), providing a way to create a 'Car' object with specific attributes.

Constructors ensure that when an object is created, its attributes are initialized to avoid undefined behavior. In the default constructor, the make and model strings are initialized to an empty string, and the numeric values are set to zero. The parameterized constructor allows initializing with particular values, directly expressing the intention of creating a 'Car' with specific attributes.

Array Initialization in C++

Initializing arrays in C++ can be done in several ways, depending on the context and data type of the array. For arrays of simple data types, such as int or double, you can use curly braces with a list of values. For arrays of structs or objects, you need to call the constructor for each element you wish to initialize.

In the example of the 'Car' struct, to create and initialize a fixed-size array of 'Car' objects, the array is first declared with the desired number of elements. Following that, specific elements of the array can be initialized by calling the 'Car' constructor directly, passing in the desired values.

The code snippet shows the initialization of the first three elements with the given data for make, model, year, and cost. The rest of the 'Car' objects in the 'forsale' array will remain uninitialized or hold default values if a default constructor is provided, as seen in the exercise. It is essential to correctly initialize each element to prevent accessing uninitialized memory, which can lead to unpredictable behavior in the program.