Horje
How to check if an object has a specific property in JavaScript?

In JavaScript, you can check if an object has a specific property using various methods, such as the hasOwnProperty() method, the in operator, or using the Object.keys() method.

Here’s how you can achieve it using these methods:

Using the hasOwnProperty() method

The hasOwnProperty() method checks if an object has a property with the specified name. It returns true if the object has the property directly on itself (not inherited from its prototype chain), otherwise it returns false.

const obj = { name: "John", age: 30 };

console.log(obj.hasOwnProperty("name")); // Output: true
console.log(obj.hasOwnProperty("gender")); // Output: false

Using the in operator

The in operator checks if an object has a property with the specified name, including properties inherited from its prototype chain. It returns true if the property exists, otherwise it returns false.

const obj = { name: "John", age: 30 };

console.log("name" in obj); // Output: true
console.log("gender" in obj); // Output: false

Using the Object.keys() method

The Object.keys() method returns an array of a given object’s own enumerable property names. You can then check if the property exists by searching for its name in the array.

const obj = { name: "John", age: 30 };

console.log(Object.keys(obj).includes("name")); // Output: true
console.log(Object.keys(obj).includes("gender")); // Output: false



Reffered: https://www.geeksforgeeks.org


JavaScript

Related
What is Array.flatMap() in JavaScript? What is Array.flatMap() in JavaScript?
What is Object.defineProperty() in JavaScript? What is Object.defineProperty() in JavaScript?
What is Array.join() method in JavaScript? What is Array.join() method in JavaScript?
What is function scope in JavaScript? What is function scope in JavaScript?
How to use innerHTML in JavaScript ? How to use innerHTML in JavaScript ?

Type:
Geek
Category:
Coding
Sub Category:
Tutorial
Uploaded by:
Admin
Views:
14