Classes and objects

9 min 20 XP + 10 for no hints

A class is a blueprint and an object is one thing made from it. Classes bundle data, called fields, with methods that work on that data.

Create an object with new: Book b = new Book();. Then use a dot to set data and call methods: b.Title = "Wonder";

Mark members public so other code can use them. These methods aren't static: each object has its own data, so you call them on an object.

Example

class Dog
{
    public string Name;
    public void Bark()
    {
        Console.WriteLine($"{Name} says woof!");
    }
}

// inside Main:
Dog rex = new Dog();
rex.Name = "Rex";
rex.Bark();

Output

Rex says woof!

One class can make as many objects as you like, and each one keeps its own data.

Your tasks

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Define class Car
Give it a public string Model
Add a public void Honk() that prints "Beep!"
Create a Car with new and call Honk()

Quick check

Which keyword creates a new object in C#?

Program.csChecked as you type

using System;

// Write a class Car with a public string Model
// and a public method Honk() that prints "Beep!"


class Program
{
    static void Main()
    {
        // Create a Car with new, set its Model and call Honk()

    }
}

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Classes and objects

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