Object

`Object.hasOwn`

Returns true if the specified object has the indicated property as its own property, intended as a replacement for Object.prototype.hasOwnProperty

Syntax

JavaScript

Object.hasOwn(obj, prop)

Parameters

Parameter	Type	Description
obj	object	The object to test
prop	string \| symbol	The property to test

Return Value

true if the object has the specified property as own property, false otherwise

Examples

Basic Usage

const obj = { name: 'Alice' };
console.log(Object.hasOwn(obj, 'name')); // true
console.log(Object.hasOwn(obj, 'toString')); // false

Practical Example

const map = Object.create(null);
map.key = 'value';
console.log(Object.hasOwn(map, 'key')); // true

Advanced Usage

const arr = [1, 2, 3];
console.log(Object.hasOwn(arr, '0')); // true
console.log(Object.hasOwn(arr, 'length')); // true

Understanding Object.hasOwn

The Object.hasOwn method in JavaScript returns true if the specified object has the indicated property as its own property, intended as a replacement for Object.prototype.hasOwnProperty. It belongs to the Object object and is one of the most widely used methods for working with object values in modern JavaScript and TypeScript applications.

The method signature is Object.hasOwn(obj, prop). It accepts 2 parameters: obj, prop. When called, it returns true if the object has the specified property as own property, false otherwise. Understanding when and how to use hasOwn() helps you write more expressive, readable code.

Common use cases for Object.hasOwn include data transformation, input validation, API response processing, and building reusable utility functions. It works well alongside related methods like object-keys, object-getownpropertynames, enabling you to chain operations together for complex data manipulation pipelines.

Supported in Chrome 93+, Firefox 92+, Safari 15.4+, Edge 93+, and Node.js 16.9+.