JavaScript Object.isSealed()

Definition and usage

Object.isSealed() The method is used to check if an object is sealed. If the object is sealed, it returns true.

Related methods:

Object.preventExtensions() Allow modification, but prevent the addition of properties.

Object.seal() Allows modification, but prevents addition and deletion of properties.

Object.freeze() Prevents modification, addition, and deletion of properties.

Object.isExtensible() Returns true if the object is extensible.

Object.isSealed() Returns true if the object is sealed.

Object.isFrozen() Returns true if the object is frozen.

Instance

Example 1

// Create an object
const person = {firstName: "Bill", lastName: "Gates"};
// Seal the object
Object.seal(person);
// This will return true
let answer = Object.isSealed(person);

Try It Yourself

Example 2

// Create an array
const fruits = ["Banana", "Orange", "Apple", "Mango"];
// Seal the array
Object.seal(fruits);
// This will return true
let answer = Object.isSealed(fruits);

Try It Yourself

Syntax

Object.isSealed(object)

Parameter

Return Value

Browser Support

Object.isSealed() It is a feature of ECMAScript5 (ES5).

Since July 2013, all modern browsers have fully supported ES5 (JavaScript 2009):