Question

The structure car is declared as follows: struct Car string carMake; string carModel; int yearmodel; double cost Write a definition statement that defines a car structure variable initialized with the following data: Make: Ford Model: Mustang Year Model: 1968 cost: \(\$ 20,000\)

Short answer

Question: Define a Car structure variable and initialize it with the given data: a Ford Mustang, year model 1968, and cost of $20,000. Answer: To define and initialize a Car structure variable, follow these steps: 1. Define the Car structure variable by declaring a variable of type 'Car' and giving it a name, for example, 'myCar': Car myCar; 2. Initialize the fields of the structure with the given data by assigning each value to the corresponding field inside the struct: myCar.carMake = "Ford"; myCar.carModel = "Mustang"; myCar.yearModel = 1968; myCar.cost = 20000; Now, the Car structure variable 'myCar' is initialized with the given data: Make - Ford, Model - Mustang, Year Model - 1968, and cost - $20,000.

Step-by-step solution

1. Define the Car structure variable

To define the Car structure variable, simply declare a variable of type 'Car' and give it a name, for example 'myCar'. Car myCar;

2. Initialize the Car variable

Now initialize the fields of the structure with the given data. Assign each value to the corresponding field inside the struct: myCar.carMake = "Ford"; myCar.carModel = "Mustang"; myCar.yearModel = 1968; myCar.cost = 20000; Now, the Car structure variable 'myCar' is initialized with the given data: Make - Ford, Model - Mustang, Year Model - 1968, and cost - $20,000.

Key concepts

C++ variables

Variables in C++ are placeholders for storing data values during the execution of a program. They are fundamental to programming as they enable you to write code that manipulates and uses data efficiently. A variable provides a named storage that our programs can manipulate. Each variable in C++ has a specific data type, which determines the size and layout of the variable's memory, the range of values that can be stored, and the set of operations that can be applied to the variable.

When you declare a variable, you must give it a type and a name. The name is used to access the variable in the code. For example, in the given exercise, `myCar` is a variable of type `Car`. This makes `myCar` a structured variable that can hold multiple pieces of information, like carMake, carModel, yearModel, and cost, all of which are part of the `Car` struct.

• The type of variable (e.g., int, string, double)
• Variable name (e.g., myCar)

Understanding variable names and types is crucial because they dictate how you can use the variable in your program. Declaring variables correctly is the first step to using them effectively in C++.

data initialization

Data initialization refers to the process of assigning an initial value to a variable at the time of its creation. It's a best practice in programming because it prevents using garbage or default values, which can lead to unpredictable results.
In C++, you can initialize variables using assignment statements. For instance, when you have a structured variable like `myCar`, you initialize it by assigning values to each member of the struct.

In the provided exercise, the initialization of the `Car` variable involves directly assigning values:

• `myCar.carMake = "Ford";` - Initializes the carMake field with the string "Ford".
• `myCar.carModel = "Mustang";` - Assigns "Mustang" to the carModel field.
• `myCar.yearModel = 1968;` - Stores the integer 1968 in yearModel.
• `myCar.cost = 20000;` - Sets the double cost to 20000.0.

Initializing your variables at the earliest possibility helps in making your code more reliable and easier to read, as it provides clear initial conditions for each element in your program.

C++ data types

Data types in C++ are categories of data that tell the compiler or interpreter how the programmer intends to use the data. They are crucial in determining the nature of operations that can be performed on the data and the amount of memory to be reserved.

In the context of the exercise, there are several data types used for creating the `Car` struct. These include:

• String: This data type is used for storing sequences of characters, such as words or sentences. The data type `string` is used for variables `carMake` and `carModel` to hold names like "Ford" and "Mustang".
• Int: Short for integer, this data type is used with the `yearModel` to represent whole numbers. Here it is used to store the value 1968, the year of the car model.
• Double: This data type represents floating-point numbers, which include decimal points. The `cost` field uses a `double` to store car prices to allow for precise values, even if they contain fractions or need to represent large numbers.

Choosing the correct data type is essential to ensure that your program operates correctly and efficiently. It affects performance and the range of values your program can handle, thereby guiding how you utilize and manipulate data in C++.