How to Check If An Object is Empty in JavaScript

In this article, I will be sharing different ways to check if an object is empty in JavaScript.

Let's start with creating an empty object using literal syntax.

const myObject = {}

1. Object.entries()

This method returns an array containing the [key, value] pairs found in the object passed in as an argument.
To check if an object is empty, check if the length of the array is 0.

Object.entries(myObject).length === 0;
// 0

return Object.entries(myObject).length === 0 ? true: false
// true

2. Object.keys()

This method returns an array of strings that contains enumerable properties of the object passed as an argument. It returns an array of [ keys ]

Object.keys(myObject).length === 0;
// 0

return Object.keys(myObject).length === 0 ? true: false
// true

You can also create an isEmpty function and pass in the object as a parameter

function isEmpty (myObject) {

return Object.keys(myObject).length === 0 ? true: false

}

isEmpty(myObject); // true

3. Object.getOwnPropertyNames()

It returns an array of strings that corresponds to the properties found in the object passed as an argument. This method calls GetOwnPropertyKeys under the hood.

 Object.getOwnPropertyNames(myObject).length === 0;
// 0

if(Object.getOwnPropertyNames(myObject).length === 0) { // return something};

4. !myObject.key

It checks if the [key] is present in myObject. Use this when you know the properties that the object is supposed to have.

let result = '';

my.object.id // undefined

if (!myObject.id) result = 'object is empty'

console.log(result) // object is empty

Note: this won't work myObject[id], JavaScript will throw an error.

Using a JavaScript Library

5. UnderScore.js

_.isEmpty(collection) Returns true if collection has no elements. For strings and array-like objects _.isEmpty checks if the length property is 0.

_.isEmpty([1, 2, 3]);

=> false

_.isEmpty({});

=> true

6. Lodash.Js

_.isEmpty() Method Checks if the value is an empty object, collection, map, or set. Objects are considered empty if they have no own enumerable string keyed properties.

_.isEmpty({ 'a': 1 });
// => false

_.isEmpty(myObject)
// true