Understanding the JavaScript instanceof Operator

Let’s dive into the fundamentals of the JavaScript instanceof operator, which is used to determine if an object is an instance of a specific class or its ancestor in the prototype chain.

In the following example, we have an object called myCar, which is an instance of the Fiesta class. The instanceof operator allows us to check if myCar is an instance of Fiesta or Car (since Fiesta extends Car).

class Car {}
class Fiesta extends Car {}

const myCar = new Fiesta();
myCar instanceof Fiesta; // true
myCar instanceof Car; // true

By using the instanceof operator, we obtain true for both myCar instanceof Fiesta and myCar instanceof Car.

Using the instanceof operator can be helpful in scenarios where you need to ensure that an object belongs to a specific class or has inherited properties and methods from a particular ancestor.

With a clear understanding of the JavaScript instanceof operator, you can confidently utilize it to check object instances and their relationships in your JavaScript applications.

tags: [“JavaScript”, “instanceof operator”]