Instance fields and state in C Sharp (C#) - Mini Project: Build & Apply

Instance Fields and State in C#

📖 Scenario: Imagine you are creating a simple program to keep track of a car's details and its current speed. Each car has its own color and speed, which can change over time.

🎯 Goal: You will build a Car class with instance fields to store the car's color and speed. Then, you will create a car object, update its speed, and display its current state.

📋 What You'll Learn

Create a class called Car with instance fields color and speed

Create an object of the Car class with a specific color

Add a method to update the car's speed

Print the car's color and current speed

💡 Why This Matters

🌍 Real World

Tracking the state of objects like cars, users, or products is common in software. Instance fields store each object's unique data.

💼 Career

Understanding instance fields and object state is fundamental for programming jobs involving object-oriented design and development.

1

Create the Car class with instance fields

Create a class called Car with two instance fields: a string called color and an int called speed. Initialize speed to 0 inside the class.

C Sharp (C#)

public class Car
{
    // Your code here
}

Need a hint?

Instance fields are variables inside a class that hold data for each object.

2

Create a Car object with a color

Create a Car object called myCar and set its color field to "Red".

C Sharp (C#)

public class Car
{
    public string color;
    public int speed = 0;
}

// Your code here

Need a hint?

Use new Car() to create an object and set the color field directly.

3

Add a method to update the speed

Inside the Car class, add a public method called SetSpeed that takes an int parameter called newSpeed and sets the instance field speed to newSpeed.

C Sharp (C#)

public class Car
{
    public string color;
    public int speed = 0;
    // Your code here
}

Car myCar = new Car();
myCar.color = "Red";

Need a hint?

Methods inside a class can change the instance fields to update the object's state.

4

Update speed and print car details

Use the SetSpeed method on myCar to set the speed to 60. Then, print the car's color and speed in the format: "Car color: Red, Speed: 60".

C Sharp (C#)

public class Car
{
    public string color;
    public int speed = 0;

    public void SetSpeed(int newSpeed)
    {
        speed = newSpeed;
    }
}

Car myCar = new Car();
myCar.color = "Red";

// Your code here

Need a hint?

Use the method to update speed and Console.WriteLine with an interpolated string to print.