Sometimes you need to retrieve the name of a class in JavaScript. This is helpful for debug messages or when using the class name as an identifier. Retrieving the class name in JavaScript is different for static and instance methods.
This tutorial walks you through the individual method types and shows you how to access the class name.
Node.js Series Overview
- String Replace All Appearances
- Remove All Whitespace From a String in JavaScript
- Generate a Random String in Node.js or JavaScript
- Remove Extra Spaces From a String in JavaScript or Node.js
- Remove Numbers From a String in JavaScript or Node.js
- Get the Part Before a Character in a String in JavaScript or Node.js
- Get the Part After a Character in a String in JavaScript or Node.js
- How to Check if a Value is a String in JavaScript or Node.js
- Check If a String Includes All Strings in JavaScript/Node.js/TypeScript
- Check if a Value is a String in JavaScript and Node.js
- Limit and Truncate a String to a Given Length in JavaScript and Node.js
- Split a String into a List of Characters in JavaScript and Node.js
- How to Run an Asynchronous Function in Array.map()
- How to Reset and Empty an Array
- for…of vs. for…in Loops
- Clone/Copy an Array in JavaScript and Node.js
- Get an Array With Unique Values (Delete Duplicates)
- Sort an Array of Integers in JavaScript and Node.js
- Sort a Boolean Array in JavaScript, TypeScript, or Node.js
- Check If an Array Contains a Given Value in JavaScript or Node.js
- Add an Item to the Beginning of an Array in JavaScript or Node.js
- Append an Item at the End of an Array in JavaScript or Node.js
- How to Exit and Stop a for Loop in JavaScript and Node.js
- Split an Array Into Smaller Array Chunks in JavaScript and Node.js
- How to Get an Index in a for…of Loop in JavaScript and Node.js
- How to Exit, Stop, or Break an Array#forEach Loop in JavaScript or Node.js
- Retrieve a Random Item From an Array in JavaScript or Node.js
- Callback and Promise Support in your Node.js Modules
- Run Async Functions/Promises in Sequence
- Run Async Functions/Promises in Parallel
- Run Async Functions in Batches
- How to Fix “Promise resolver undefined is not a function” in Node.js or JavaScript
- Detect if Value Is a Promise in Node.js and JavaScript
- Extend Multiple Classes (Multi Inheritance)
- Retrieve the Class Name at Runtime in JavaScript and Node.js
- Get a File’s Created Date
- Get a File’s Last Modified/Updated Date
- How to Create an Empty File
- Check If a Path or File Exists
- How to Rename a File
- Check If a Path Is a Directory
- Check If a Path Is a File
- Retrieve the Path to the User’s Home Directory
- How to Touch a File
- Read File Content as String
- Check If a Directory Is Empty
In Static Methods
Retrieving the class name in static methods is pretty straightforward. Because JavaScript represents classes as functions, you can access the name property to retrieve the name of the class.
Retrieve the class name in static methods by either using this.name or Class.name:
class User {
/**
* Returns the string 'User'.
*
* @returns {String}
*/
static className() {
return this.name
// is the same as
// return User.name
}
}
console.log(
User.className()
)
// 'User'
Be Aware of a Static “name“ Property in Classes
There’s a pitfall you should be aware of. When defining a static name property in your class, it will overwrite the name property of the class.
class User {
/**
* Returns the name.
*
* @returns {String}
*/
static get name () {
return 'Marcus'
}
/**
* Returns the string 'Marcus' because the static `name`
* property overwrites the name property of the class.
*
* @returns {String}
*/
static className() {
return this.name
}
}
console.log(
User.className()
)
// 'Marcus'
It’s recommended to use a static name property with caution when working with JavaScript’s classes. It can be a helpful way to customize the class name to your own needs.
In Instance Methods
You can access the class name in instance methods using either the constructor or the class itself. The constructor is available via this.constructor and provides the class properties:
class User {
/**
* Returns the string 'User'.
*
* @returns {String}
*/
className() {
return this.constructor.name
// is the same as
// return User.name
}
}
console.log(
User.className()
)
// 'User'
Text
Having a Static “name“ Property in Classes
Please notice, having a static name property on your class overrides the actual class name:
class User {
/**
* Returns the name.
*
* @returns {String}
*/
static get name () {
return 'Marcus'
}
/**
* Returns the string 'Marcus' because the static `name`
* property overwrites the name property of the class.
*
* @returns {String}
*/
static className() {
return this.constructor.name
}
}
console.log(
User.className()
)
// 'Marcus'
That’s it about accessing the class name from static and instance methods. If you know of another way to access the class name, please share it in the comments below!