Notion app logo
Struggling to stay organized and effective? Learn to master your time and tasks with the Effectively Notion course!

Interpolate a JavaScript variable for an object key

Learn how to interpolate a JavaScript variable for an object key for dynamic keys in a JavaScript object.



In JavaScript programming, a common requirement is the ability to use dynamic keys in objects. This article will provide a comprehensive guide on how to handle such scenarios effectively.


A basic understanding of JavaScript and familiarity with the concept of JavaScript objects is needed to fully grasp the methods discussed in this article.


The primary aim is to elucidate two different methods of using dynamic keys when working with JavaScript objects.

Step-by-Step Guide

Method 1: Initializing an Object with Dynamic Keys

Initially, you may find yourself working with a simple object with static key-value pairs, as shown below:

const args = { 	StaticKey: "some value" }

However, when a dynamic key is needed, the following approach can be employed. For this example, a constant with the string value DynamicKey is created.

const someKey = "DynamicKey"

Next, this constant is used as a key in our object, replacing the static DynamicKey.

const myDynamicObject = { 	[someKey]: "some value" };

In this instance, the key is surrounded by square brackets ([ ]). This syntax instructs JavaScript to treat the enclosed variable as the key's value.

An output of the object would appear as follows:

const someKey = "DynamicKey" ;
const myDynamicObject = { 	[someKey]: "some value" };  
console.log(myDynamicObject); // {DynamicKey: "some value"}

Method 2: Adding Dynamic Key-Value Pairs to Existing Object

Once myDynamicObject is defined and DynamicKey has been established, another key-value pair can be added to the existing object using a dynamic key.

Assuming another dynamic key is required, the following code accomplishes this:

const secondKey = "unicorns are";
myDynamicObject[secondKey] = "awesome sauce"

The console.log function will output the myDynamicObject object as shown:

{ 	"unicorns are": "awesome sauce",  DynamicKey: "some value" }

Tips and Best Practices

It's important to use dynamic keys appropriately. While they provide flexibility, overuse can lead to unclear and unpredictable code.


This tutorial has demonstrated two techniques for using dynamic keys with JavaScript objects, providing a foundation for more flexible and dynamic coding practices.

Additional Resources

To further your understanding of JavaScript objects, the following resources are recommended:

These resources should enhance your JavaScript proficiency and aid in producing efficient, dynamic code.

Photo of Chase Adams

Hey, I'm Chase. I help aspiring entrepreneurs and makers turn their ideas into digital products and apps.


Vector Arrow Scribbles
banner image for figma vector arrows scribbles

A figma community project of vectorized hand-drawn arrows.

Go To Figma
Vector Line Scribbles
banner for figma vector line scribbles

A figma community project of vectorized hand-drawn lines.

Go To Figma
Vector Shape Scribbles
banner image of figma vector shapes scribbles

A figma community project of vectorized hand-drawn shapes.

Go To Figma

Subscribe to my Newsletter

Every other week I publish the Curiously Crafted newsletter.

In it, I explore the intersection of curiosity and craft: the people who make stuff, what they make and the way they pursue the craft of making.


I'm on almost all social media as @curiouslychase.

The curious logo of Chase Adams: glasses and a bow tie.stay curious.