How to Use Object.hasOwn in JavaScript: Syntax and Examples

Use Object.hasOwn(object, property) to check if an object has a specific own property. It returns true if the property exists directly on the object, otherwise false. This method is a modern and safer alternative to hasOwnProperty.

Syntax

The syntax for Object.hasOwn is simple:

• object: The object you want to check.
• property: The name of the property you want to check for, as a string or symbol.

The method returns true if the property exists directly on the object (not inherited), otherwise false.

javascript

Object.hasOwn(object, property)

Example

This example shows how to use Object.hasOwn to check if an object has a specific property:

javascript

const car = { brand: 'Toyota', year: 2020 };

console.log(Object.hasOwn(car, 'brand')); // true
console.log(Object.hasOwn(car, 'color')); // false

// Checking inherited property
const parent = { wheels: 4 };
const child = Object.create(parent);
child.doors = 2;

console.log(Object.hasOwn(child, 'doors')); // true
console.log(Object.hasOwn(child, 'wheels')); // false (inherited, not own)

Output

true
false
true
false

Common Pitfalls

Common mistakes when checking properties include:

• Using in operator which checks inherited properties too.
• Using hasOwnProperty directly on objects that might not have it (e.g., objects created with Object.create(null)).

Object.hasOwn avoids these issues by being a static method on Object and always safe to use.

javascript

const obj = Object.create(null);
obj.key = 'value';

// Wrong: obj.hasOwnProperty might not exist
// console.log(obj.hasOwnProperty('key')); // Error

// Right: use Object.hasOwn
console.log(Object.hasOwn(obj, 'key')); // true

Output

true

Quick Reference

Method	Description	Returns
Object.hasOwn(object, property)	Checks if property is own property of object	true or false
object.hasOwnProperty(property)	Checks if property is own property (may fail if method missing)	true or false
property in object	Checks if property exists anywhere in object (own or inherited)	true or false

Key Takeaways

Use Object.hasOwn(object, property) to safely check own properties.

It returns true only if the property exists directly on the object.

Avoid using hasOwnProperty on objects that may lack it, like Object.create(null).

The in operator checks inherited properties too, so it is not the same.

Object.hasOwn is a modern, reliable alternative introduced in recent JavaScript versions.