JavaScript object.isSealed() method is used to determine if an object is sealed or not. An object is sealed if all of the below-mentioned conditions hold true :
- If it is not extensible.
- If all of its properties are non-configurable.
- If it is not removable (but not necessarily non-writable).
Object.isSealed() takes the object as an argument that has to be checked and returns a boolean representing whether the object is sealed or not.
Syntax:
Object.isSealed(obj)
Parameters:
- obj: It is the object which has to be checked.
Return Value: Object.isSealed() returns a boolean representing whether the object is sealed or not.
Examples of the above function are provided below.
Example 1: In the above example the object has not been sealed using the Object.seal() method, therefore, it returns false when it is checked using Object.isSealed() method.
Javascript
// creating an object constructor// and assigning values to itconst object = { property: 'hi neveropen'};// checking whether the object// is sealed or notconsole.log(Object.isSealed(object)); |
Output:
false
Example 2: In the above example the object has been sealed using the Object.seal() method, therefore, it returns true when it is checked using Object.isSealed() method.
Javascript
// creating an object constructor// and assigning values to itconst object = { property: 'hi neveropen'};// Using seal() method to seal the objectObject.seal(object);// checking whether the// object is frozen or notconsole.log(Object.isSealed(object)); |
Output:
true
Applications:
- Object.isSealed() is used for checking whether an object is sealed or not.
Exceptions :
- It causes a TypeError if the argument passed is not an object.
- If an object is not passed as an argument to the method, then it treats it as a sealed object and returns true.
We have a complete list of Javascript Object methods, to check those please go through this JavaScript Object Complete Reference article.
Supported Browsers:
- Chrome 6 and above
- Edge 12 and above
- Firefox 4 and above
- Internet Explorer 9 and above
- Opera 12 and above
- Safari 5.1 and above
