How to get the Class Name of an Object in JavaScript

In this article, we will learn how we can get the class Name of an Object with multiple approaches in JavaScript.

In JavaScript, determining an object's class name can be done using multiple approaches. The constructor property of an object reveals the function that created it, while the instanceof operator checks if an object is an instance of a class. Additionally, employing Object.prototype.toString() method with the object as an argument helps retrieve its class name in string form. These methods help in identifying the class of an object, help in handling different types of objects within JavaScript programs.

Approach 1: Using the constructor Property

In JavaScript, the constructor property serves as a tag on an object, showing the function that formed it. It's a means to discover which constructor function was used to craft the object. By using object.constructor, you can simply finds the object's category without going into complexities, offering a clear path to recognize object types in JavaScript.

Example: In this example we will see how to find the Class Name of an Object using the constructor Property in JavaScript.

class Product {
    constructor(name, price) {
        this.name = name;
        this.price = price;
    }

    getClassName() {
        return this.constructor.name;
    }
}

const product = new Product("Book", 10);
console.log(product.getClassName()); 

Ouput:

Product

Approach 2: Using the instanceof Operator

By utilizing the 'instanceof' check in JavaScript, we determine if an object belongs to a particular category, It's like asking if something is a part of a certain group. For example, employing 'instanceof' aids in understanding if an object aligns with a defined type, offering insights into its classification within the code.

Example: In this example we will see how to find the Class Name of an Object Using the instanceof Operator in JavaScript.

class Product {
    constructor(name) {
        this.name = name;
    }

    // Check if the given object is an 
    // instance of the Product class.
    isInstanceOfProduct(object) {
        return object instanceof Product;
    }
}

const product = new Product("Book");

// Check if the product object is an
// instance of the Product class.
const isInstanceOfProduct = 
product.isInstanceOfProduct(product);
console.log(isInstanceOfProduct);

Output:

true

Conclusion :

In JavaScript, determining an object's class name is essential for understanding its type. Using the constructor property offers a straightforward method, revealing the function that created the object. Meanwhile, the instanceof operator provides a simple way to confirm if the object is an instance of a specific class. Both approaches contribute to identifying the object's class, aiding in clearer classification and better understanding of its type within the code.