1. Adding Properties
You can add new properties to an object in multiple ways:
✅ Dot notation
let user = {};
user.name = "John";
user.age = 25;
console.log(user); // { name: "John", age: 25 }
✅ Bracket notation (useful for dynamic keys or keys with spaces/special chars)
let user = {};
user["email"] = "john@example.com";
let key = "phoneNumber";
user[key] = "1234567890";
console.log(user); // { email: "john@example.com", phoneNumber: "1234567890" }
✅ Object.assign() (merge properties into an object)
let user = { name: "John" };
Object.assign(user, { age: 25, country: "India" });
console.log(user); // { name: "John", age: 25, country: "India" }
✅ Spread operator (...)
let user = { name: "John" };
user = { ...user, age: 25, country: "India" };
console.log(user); // { name: "John", age: 25, country: "India" }
2. Removing Properties
✅ delete operator
let user = { name: "John", age: 25 };
delete user.age;
console.log(user); // { name: "John" }
⚠️ Note: delete removes a property from the object but does not affect the prototype.
✅ Destructuring + rest (...)
let user = { name: "John", age: 25, country: "India" };
let { age, ...rest } = user;
console.log(rest); // { name: "John", country: "India" }
(This doesn’t mutate the original object; instead, it creates a new one without age.)
✅ Summary:
- Add:
obj.prop = value,obj["key"] = value,Object.assign(), spread operator. - Remove:
delete obj.prop, or create a new object without that property using destructuring.