The Object.seal function in JavaScript is utilized to seal an object, thereby disallowing the addition of new properties and designating all current properties as non-configurable. The object intended for sealing is provided as a parameter, and the method subsequently returns the sealed object.
Syntax:
Example
Object.seal(obj)
Parameter:
obj : It is the object which should be sealed.
Return value:
The Object.sealed function returns the object that has been sealed.
Browser Support:
| Chrome | 6 |
|---|---|
Edge |
Yes |
| Firefox | 4 |
| Opera | 12 |
Example 1
Example
const obj1 = { property1: 'Marry'};
const obj2 = Object.seal(obj1);
// prevents other code from deleting properties of an object.
obj2.property1 = 'carry';
console.log(obj2.property1);
Output:
Output
"carry"
Example 2
Example
const object1 = {
property1: 29
};
Object.seal(object1);
// Prevents other code from deleting properties of an object.
object1.property1 =45;
console.log(object1.property1);
delete object1.property1;
// cannot delete when sealed
Output:
Example 3
Example
const object1 = {
property1: 42
};
Object.seal(object1);
object1.property1 = 45;
console.log(object1.property1);
delete object1.property1; // cannot delete when sealed
console.log(object1.property1);
const object2 = {
property2: 45};
object2.property2 =67;
console.log(object2.property2);
Output:
Output
45
45
67
