Spread

Array Spread

const itemList = [1, 2, 3];
const additionalItemList = [5, 6];

const newItemList = [...itemList, 4, ...additionalItemList];

console.log(newItemList); // [1, 2, 3, 4, 5, 6]

Object Spread

Très pratique pour respecter l'immutabilité.

const user = {
    firstName: 'Foo',
    lastName: 'BAR',
    email: '[e-mail]'
};

const newUser = {
    ...user,
    email: '[e-mail]',
    phoneNumber: '[phone]'
};

console.log(newUser);
// {
//    firstName: 'Foo',
//    lastName: 'BAR',
//    email: '[e-mail]',
//    phoneNumber: '[phone]'
//}