Learn Challenge: `static` Keyword

In this problem, you need to:

Create a new private field called totalCars of type double which tracks the total number of Car objects created;
Create a getter method called getTotalCars which simply returns the number of objects;
Make sure the value of the totalCars field is incremented every time a new Car object is created.

index.cs


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using System;

class Car
{
    int modelYear;
    double mileage;
    string brandName;

    public Car(string brandName, int modelYear, double mileage)
    {
        this.brandName = brandName;
        this.modelYear = modelYear;
        this.mileage = mileage;

        // Write code below this line

        // Write code above this line 
    }

    // Write code below this line

    // Write code above this line
}

class ConsoleApp
{

    static void Main()
    {
        Console.WriteLine(Car.getTotalCars());

        Car car1 = new Car("Toyota", 2022, 25.5);
        Car car2 = new Car("Honda", 2020, 30.2);
        Car car3 = new Car("Ford", 2021, 28.8);

        Console.WriteLine(Car.getTotalCars());
    }
}

The field which tracks the number of objects should be static because it always stores some data.
It was explained in the Access Modifiers chapter that a getter method is simply a public method which returns the value of a private field. In this case getTotalCars should return totalCars.
The getTotalCars method should also be static because we want to use it without an instance.

index.cs


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using System;

class Car
{
    int modelYear;
    double mileage;
    string brandName;

    public Car(string brandName, int modelYear, double mileage)
    {
        this.brandName = brandName;
        this.modelYear = modelYear;
        this.mileage = mileage;

        // Write code below this line
        totalCars += 1;
        // Write code above this line
    }

    // Write code below this line
    private static double totalCars;

    public static double getTotalCars()
    {
        return totalCars;
    }
    // Write code above this line
}

class ConsoleApp
{
    static void Main()
    {
        Console.WriteLine(Car.getTotalCars());

        Car car1 = new Car("Toyota", 2022, 25.5);
        Car car2 = new Car("Honda", 2020, 30.2);
        Car car3 = new Car("Ford", 2021, 28.8);

        Console.WriteLine(Car.getTotalCars());
    }
}

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Thanks for your feedback!

Section 4. Chapter 6

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In this problem, you need to:

Create a new private field called totalCars of type double which tracks the total number of Car objects created;
Create a getter method called getTotalCars which simply returns the number of objects;
Make sure the value of the totalCars field is incremented every time a new Car object is created.

index.cs


              1234567891011121314151617181920212223242526272829303132333435363738
            
using System;

class Car
{
    int modelYear;
    double mileage;
    string brandName;

    public Car(string brandName, int modelYear, double mileage)
    {
        this.brandName = brandName;
        this.modelYear = modelYear;
        this.mileage = mileage;

        // Write code below this line

        // Write code above this line 
    }

    // Write code below this line

    // Write code above this line
}

class ConsoleApp
{

    static void Main()
    {
        Console.WriteLine(Car.getTotalCars());

        Car car1 = new Car("Toyota", 2022, 25.5);
        Car car2 = new Car("Honda", 2020, 30.2);
        Car car3 = new Car("Ford", 2021, 28.8);

        Console.WriteLine(Car.getTotalCars());
    }
}

The field which tracks the number of objects should be static because it always stores some data.
It was explained in the Access Modifiers chapter that a getter method is simply a public method which returns the value of a private field. In this case getTotalCars should return totalCars.
The getTotalCars method should also be static because we want to use it without an instance.

index.cs


              123456789101112131415161718192021222324252627282930313233343536373839404142
            
using System;

class Car
{
    int modelYear;
    double mileage;
    string brandName;

    public Car(string brandName, int modelYear, double mileage)
    {
        this.brandName = brandName;
        this.modelYear = modelYear;
        this.mileage = mileage;

        // Write code below this line
        totalCars += 1;
        // Write code above this line
    }

    // Write code below this line
    private static double totalCars;

    public static double getTotalCars()
    {
        return totalCars;
    }
    // Write code above this line
}

class ConsoleApp
{
    static void Main()
    {
        Console.WriteLine(Car.getTotalCars());

        Car car1 = new Car("Toyota", 2022, 25.5);
        Car car2 = new Car("Honda", 2020, 30.2);
        Car car3 = new Car("Ford", 2021, 28.8);

        Console.WriteLine(Car.getTotalCars());
    }
}

Everything was clear?

Thanks for your feedback!

Section 4. Chapter 6