typescript解构赋值怎么指定类型？

Question

下面有一个解构赋值，[invoice, customers] 中两个元素的推断类型分别是 const invoice 和 const customers：

const [invoice, customers] = await Promise.all([    fetchInvoiceById(id),    fetchCustomers(),]);const invoice: {    amount: number;    id?: string | undefined;    date?: string | undefined;    status?: $Enums.InvoiceStatus | undefined;    customerId?: string | undefined;}const customers: {    id: string;    name: string;    email: string;    image_url: string;}[]

现在我要把下面两个类型手动指定给 [invoice, customers] 中对应的元素，即 invoice 的类型为 InvoiceForm，customers 的类型为 CustomerField，语法应该怎么写？

type InvoiceForm = {    id: string;    customerId: string;    amount: number;    status: 'pending' | 'paid';};type CustomerField = {    id: string;    name: string;};

Answer 1

const [invoice, customers]: [InvoiceForm, CustomerField] = await Promise.all([  fetchInvoiceById(id),  fetchCustomers(),]);

Answer 2

你可以在解构赋值时直接指定类型，如下：

const [invoice: InvoiceForm, customers: CustomerField[]] = await Promise.all([    fetchInvoiceById(id),    fetchCustomers(),]);

这样，invoice的类型就会被推断为InvoiceForm，而customers的类型会被推断为CustomerField[]。