How constructor chaining works in C Sharp (C#) - Try It Yourself

How constructor chaining works

📖 Scenario: Imagine you are creating a simple program to represent a Car. Different cars can have different details like brand, model, and year. You want to use constructor chaining to make your code cleaner and avoid repeating yourself.

🎯 Goal: You will build a Car class with multiple constructors that use constructor chaining. This will help you understand how one constructor can call another to reuse code.

📋 What You'll Learn

Create a class called Car with three fields: brand, model, and year.

Write a constructor that takes only brand and sets default values for model and year.

Write a constructor that takes brand and model, and calls the first constructor using constructor chaining.

Write a constructor that takes brand, model, and year, and calls the second constructor using constructor chaining.

Create an object of Car using the constructor with all three parameters.

Print the car details to show the values of brand, model, and year.

💡 Why This Matters

🌍 Real World

Constructor chaining is used in real programs to simplify object creation when there are many ways to create an object with different details.

💼 Career

Understanding constructor chaining is important for writing clean, maintainable code in object-oriented programming jobs.

1

Create the Car class with fields and first constructor

Create a class called Car with three fields: brand, model, and year. Then write a constructor that takes a string parameter brand and sets brand to this value, model to "Unknown", and year to 0.

C Sharp (C#)

class Car
{
    // Your code here
}

Need a hint?

Remember to declare the fields inside the class and write a constructor with one parameter brand. Set the other fields to default values.

2

Add second constructor with constructor chaining

Add a second constructor to the Car class that takes two string parameters: brand and model. Use constructor chaining to call the first constructor with brand, then set model to the given value.

C Sharp (C#)

class Car
{
    public string brand;
    public string model;
    public int year;

    public Car(string brand)
    {
        this.brand = brand;
        this.model = "Unknown";
        this.year = 0;
    }

    // Your code here
}

Need a hint?

Use : this(brand) after the constructor signature to call the first constructor.

3

Add third constructor with full parameters and chaining

Add a third constructor to the Car class that takes three parameters: brand, model, and year. Use constructor chaining to call the second constructor with brand and model, then set year to the given value.

C Sharp (C#)

class Car
{
    public string brand;
    public string model;
    public int year;

    public Car(string brand)
    {
        this.brand = brand;
        this.model = "Unknown";
        this.year = 0;
    }

    public Car(string brand, string model) : this(brand)
    {
        this.model = model;
    }

    // Your code here
}

Need a hint?

Use : this(brand, model) to call the second constructor and then set year.

4

Create a Car object and print its details

Create a Car object called myCar using the constructor with three parameters: "Toyota", "Corolla", and 2020. Then print the values of myCar.brand, myCar.model, and myCar.year separated by spaces.

C Sharp (C#)

class Car
{
    public string brand;
    public string model;
    public int year;

    public Car(string brand)
    {
        this.brand = brand;
        this.model = "Unknown";
        this.year = 0;
    }

    public Car(string brand, string model) : this(brand)
    {
        this.model = model;
    }

    public Car(string brand, string model, int year) : this(brand, model)
    {
        this.year = year;
    }
}

// Your code here

Need a hint?

Create the object with new Car("Toyota", "Corolla", 2020) and print the fields using Console.WriteLine with string interpolation.