Classes and Objects

Object-oriented programming is one of the most widely used programming paradigms today, and at its core are classes and objects. Understanding these concepts is critical to mastering programming logic.

Classes

A class is a structure that defines the data and behaviors that characterize a concept or type of object. In other words, it is a model, a schema, that describes the properties (attributes) and actions (methods) that objects of that type can have. For example, we can have a "Car" class that defines attributes such as color, model, brand, maximum speed, and methods such as accelerating, braking, turning on, off, etc.

Definition of a Class

In an object-oriented programming language such as Java or Python, a class is defined with a specific syntax. For example, in Java, a "Car" class could be defined as follows:

public class Car {
    private String color;
    private String template;
    private String tag;
    private int maxspeed;
    
    public void accelerate() {
        // Code to accelerate
    }
    
    public void brake() {
        // Code to brake
    }
    
    // Other methods...
}

This class definition includes the attributes (color, model, make, maxspeed) and methods (accelerate, brake) that characterize a car. Note that attributes are defined with a data type (String, int) and methods are defined with the keyword "public" followed by the method name and a pair of parentheses. Within the parentheses, parameters that the method receives can be defined.

Objects

An object is an instance of a class. That is, it is a concrete representation, a specific example of the class. If the class is the model, the object is the product made from that model. For example, we can have an object "myCar" which is an instance of the class "Car".

Continue in our app.

You can listen to the audiobook with the screen off, receive a free certificate for this course, and also have access to 5,000 other free online courses.

Or continue reading below...

Download the app

Creating an Object

To create an object of a class, we use the "new" keyword followed by the class name. For example, in Java, we could create an object "myCar" as follows:

Car myCar = new Car();

Once created, the object can have its attributes accessed and modified, and its methods called. For example:

myCar.color = "red";
meuCarro.model = "Beetle";
myCar.brand = "Volkswagen";
myCar.maxspeed = 120;

myCar.accelerate();
myCar.brake();

In summary, classes and objects are fundamental concepts in object-oriented programming. A class is a model that defines the characteristics of a type of object, and an object is a concrete instance of that model. Mastering these concepts is essential to understand programming logic and develop software in an efficient and organized way.