How to check for empty object in JavaScript? 7 Effective ways

Explore seven (7) effective ways how to check for empty objects in JavaScript.

Master the art of checking if an object is empty in JavaScript using built-in methods like Object.keys() and Object.entries() to write custom functions tailored to your needs.

We also provide clear explanations and example codes that will help you quickly and easily determine if an object is empty.

So, are you ready to learn about checking if a JavaScript object is empty? Let’s get started!

What is object in JavaScript?

An object in JavaScript, is a collection of properties, where each property has a name and a value.

A property’s value can be a primitive data type (such as a string, number, or boolean), an array, another object, or a function.

Objects are used to store and organize data and can be thought of as a container for values.

Objects in JavaScript are very versatile and can be used to represent a wide range of real-world entities, such as a data, a person, or a bank account.

They can also be used to model more abstract concepts, such as a point in space or a date and time.

Here’s an example of an object that represents a data:

let data = {
    website: "Itsourcecode",
    offers: "which offers free source codes!",
    greet: function() {
        console.log("Hello, welcome to " + this.website + " " + this.offers);
    }
};

data.greet(); 

As you can see, in our example code it defines an object called data with three properties: website, offers, and greet.

The website property has a value of “Itsourcecode”, which is a string.

The offers property has a value of “which offers free source codes!”, which is also a string.

The greet property has a value that is a function. This function logs a greeting message to the console when it is called.

The greet function uses the this keyword to access the values of the website and Offers properties of the data object.

When the function is called using the dot notation (data.greet()), the value of this is set to the data object, so this.website and this.offers refer to the values of the website and offers properties of the data object, respectively.

When you run this code, it will create the data object and then call the greet function, which will log the following message to the console.

Output:

Hello, welcome to Itsourcecode which offers free source codes!

Solutions on how to check if an object is empty in JavaScript

Here are seven (7) effective ways to check if an object is empty in JavaScript, along with example code for each method:

Using the Object.keys() method

This method returns an array of the object’s own enumerable properties. If the length of this array is 0, then the object is empty.

It’s a quick and easy way to check if an object has any properties.

Here’s an example:

function isEmpty(obj) {
return Object.keys(obj).length === 0;
}

let sampleobj1 = {};
console.log(isEmpty(sampleobj1)); 

Output:

true

Here’s another example:

function isEmpty(obj) {
return Object.keys(obj).length === 0;
}


let sampleobj2 = {a: 1};
console.log(isEmpty(sampleobj2)); 

Output:

false

Using the JSON.stringify() method

This method converts the object to a JSON string. If the resulting string is equal to an empty object string (“{}”), then the object is empty.

It’s a simple and straightforward way to check if an object is empty.

Here’s an example:

function isEmpty(obj) {
return JSON.stringify(obj) === "{}";
}

let sampleobj1 = {};
console.log(isEmpty(sampleobj1));

Output:

true

Here’s another example:

function isEmpty(obj) {
return JSON.stringify(obj) === "{}";
}

let sampleobj2 = {a: 1};
console.log(isEmpty(sampleobj2));

Output:

false

Using a for…in loop

This loop iterates over the object’s enumerable properties. If the loop does not execute even once, then the object is empty.

It’s a more traditional way to check if an object has any properties.

Here’s an example:

function isEmpty(obj) {
for (let key in obj) {
if (obj.hasOwnProperty(key)) return false;
}
return true;
}

let sampleobj1 = {};
console.log(isEmpty(sampleobj1)); 

Output:

true

Here’s another example:

function isEmpty(obj) {
for (let key in obj) {
if (obj.hasOwnProperty(key)) return false;
}
return true;
}


let sampleobj2 = {a: 1};
console.log(isEmpty(sampleobj2)); 

Output:

false

Using the Object.entries() method:

This method returns an array of the object’s own enumerable property [key, value] pairs.

If the length of this array is 0, then the object is empty.

It’s another quick and easy way to check if an object has any properties.

Here’s an example:

function isEmpty(obj) {
    return Object.entries(obj).length === 0;
}

let sampleobj1 = {};
console.log(isEmpty(sampleobj1));

Output:

true

Here’s another example:

function isEmpty(obj) {
    return Object.entries(obj).length === 0;
}


let sampleobj2 = {a: 1};
console.log(isEmpty(sampleobj2));

Output:

false

Using the Object.getOwnPropertyNames() method

This method returns an array of all properties (including non-enumerable properties) found directly upon a given object.

If the length of this array is 0, then the object is empty. It’s a more comprehensive way to check if an object has any properties, including non-enumerable ones.

Here’s an example:

function isEmpty(obj) {
    return Object.getOwnPropertyNames(obj).length === 0;
}

let sampleobj1 = {};
console.log(isEmpty(sampleobj1)); 

Output:

true

Here’s another example:

function isEmpty(obj) {
    return Object.getOwnPropertyNames(obj).length === 0;
}

let sampleobj2 = {a: 1};
console.log(isEmpty(sampleobj2));

Output:

false

Using a combination of Object.getOwnPropertySymbols() and Object.getOwnPropertyNames() methods

These methods return arrays of all symbol and string properties (including non-enumerable properties) found directly upon a given object.

If the combined length of these arrays is 0, then the object is empty. It’s an even more comprehensive way to check if an object has any properties, including non-enumerable ones and symbol properties.

Here’s an example:

function isEmpty(obj) {
    return Object.getOwnPropertySymbols(obj).length === 0 && Object.getOwnPropertyNames(obj).length === 0;
}

let sampleobj1 = {};
console.log(isEmpty(sampleobj1)); 

Output:

true

Here’s another example:

function isEmpty(obj) {
    return Object.getOwnPropertySymbols(obj).length === 0 && Object.getOwnPropertyNames(obj).length === 0;
}

let sampleobj2 = {a: 1};
console.log(isEmpty(sampleobj2)); 

Output:

false

Using the Object.values() method

This method returns an array of the object’s own enumerable property values.

If all values in this array are undefined, then the object is empty.

It’s a slightly different approach to checking if an object has any properties with defined values.

Here’s an example:

function isEmpty(obj) {
    return Object.values(obj).every(value => value === undefined);
}

let sampleobj1 = {};
console.log(isEmpty(sampleobj1));

Output:

true

Here’s another example:

function isEmpty(obj) {
    return Object.values(obj).every(value => value === undefined);
}


let sampleobj2 = {a: 1};
console.log(isEmpty(sampleobj2));

Output:

false

Conclusion

In conclusion, we have explored seven (7) effective ways to check for empty objects in JavaScript.

These methods include using:

1. Object.keys()
2. JSON.stringify()
3. for…in loop
4. Object.entries()
5. Object.getOwnPropertyNames()
6. a combination of Object.getOwnPropertySymbols() and Object.getOwnPropertyNames(
7. and Object.values()

Each method offers a unique approach to determine if an object has no properties.

By understanding and mastering these techniques, you can easily and efficiently check for empty objects in your JavaScript code and tailor custom functions to suit your specific needs.

We are hoping that this article provides you with enough information that helps you understand the JavaScript check for empty object.

You can also check out the following article:

• JavaScript sort array
• What is event bubbling and event capturing in JavaScript.
• Clear input field JavaScript

Thank you for reading itsourcecoders 😊.