Adding new member into an object

In JavaScript, you can add a new property (or member) to an object using the dot notation or the bracket notation.

Dot Notation

const person = { name: 'John', age: 30 };
person.email = '[email protected]';
console.log(person); // Output: { name: 'John', age: 30, email: '[email protected]' }

In this example, we create an object person with two properties: name and age. We then add a new property email using the dot notation.

Bracket Notation

const person = { name: 'John', age: 30 };
person['phone'] = '123-456-7890';
console.log(person); // Output: { name: 'John', age: 30, phone: '123-456-7890' }

In this example, we create an object person with two properties: name and age. We then add a new property phone using the bracket notation.

Using the Object.assign() method

const person = { name: 'John', age: 30 };
const newProperty = { email: '[email protected]' };
Object.assign(person, newProperty);
console.log(person); // Output: { name: 'John', age: 30, email: '[email protected]' }

In this example, we create an object person with two properties: name and age. We then create a new object newProperty with a single property email. We use the Object.assign() method to merge the two objects, adding the new property to the original object.

Using the Spread Operator (ES2018+)

const person = { name: 'John', age: 30 };
const newProperty = { email: '[email protected]' };
person = {...person,...newProperty };
console.log(person); // Output: { name: 'John', age: 30, email: '[email protected]' }

In this example, we create an object person with two properties: name and age. We then create a new object newProperty with a single property email. We use the spread operator (...) to merge the two objects, adding the new property to the original object.

Note that in all cases, the new property is added to the original object, and the object is updated in place.