JS Practice — Built-in Objects

Object.isSealed() — using in practice

📖 Usage Example

// Check if an object is sealed
const obj = { a: 1 }
Object.isSealed(obj)    // → false
Object.seal(obj)
Object.isSealed(obj)    // → true

Use Object.isSealed() to check whether an object's properties cannot be added or removed (though values may still change).

Object.isSealed() — practical guard

Use Object.isSealed() to check object integrity before attempting structural changes.

Challenge: Implement tryDeleteProperty(obj, key) that deletes the property only if the object is not sealed, returning whether it was deleted.

💡 Hints (1)