JavaScript, how to get the class name of an object
If you have an object that's generated from a class, and you want to get its class name. How can you do so?
Suppose you have an object that’s generated from a class, and you want to get its class name.
For example, let’s use this code as reference:
class Dog {
}
const roger = new Dog()
Of course now we know that roger
is an object that’s created from the class Dog
.
But how do you get the class name of the object, in case you don’t know it?
You can lookup the object’s constructor, then reference its name
property.
In this example:
class Dog {
}
const roger = new Dog()
console.log(roger.constructor.name) // 'Dog'
This method returns a string that represents the class name.
You can also directly compare the constructor
property to the class, like this:
class Dog {
}
const roger = new Dog()
roger.constructor === Dog //true
I wrote 17 books to help you become a better developer, download them all at $0 cost by joining my newsletter
JOIN MY CODING BOOTCAMP, an amazing cohort course that will be a huge step up in your coding career - covering React, Next.js - next edition February 2025