What Are Methods?

Just as we can add attributes to a class, we can also add methods.

If attributes represent an object’s data, then methods represent its behavior—the actions that the object can perform.

For example, a Car class might have methods such as:

• Start the engine
• Stop the engine
• Sound the horn
• Increase speed

Adding a Method

Let’s add a method that makes the car sound its horn.

class Car {
  constructor(color, model) {
    this.color = color;
    this.model = model;
  }

  // Method
  beepSound() {
    console.log("beeeeeeeeep");
  }
}

const car = new Car("Blue", 2020);

// Call the method
car.beepSound();

Calling a Method

After creating an object, you can call any of its methods using the dot operator (.).

car.beepSound();

This tells the car object to execute its beepSound() method.

A class can contain as many methods as needed.

Why Do Methods Use Parentheses?

Notice that the method is written as:

beepSound() {}

instead of:

beepSound {}

That’s because every function or method in JavaScript uses parentheses ().

If a method accepts data, the parameter names are placed inside those parentheses.

For example:

drive(speed) {
    console.log(speed);
}

And it can be called like this:

car.drive(120);

Is the Constructor Also a Method?

Yes.

A constructor is a special method inside a class.

The difference is that you don’t call it yourself. JavaScript automatically calls it whenever you create a new object using the new keyword.

Key Takeaways

• Methods are functions defined inside a class.
• Attributes represent data, while methods represent behavior.
• Methods are called using the dot operator (.).
• Every method is written with parentheses ().
• A constructor is a special method that runs automatically when an object is created.