How should I type following destructured array?
const [first, ...rest] = this.employee.roles;
The code above works, but project rules impose const typing.
I tried:
const first: Role;
const rest: Array<Role>;
[first, ...rest] = this.employee.roles;
but then I need to change const to let for [first, ...rest] = this.employee.roles;
to work
Following code also works, but isn't it misleading?
const [first, ...rest]: Array<Role> = this.employee.roles;
since first is Role and rest is Array<Role> I'm not sure about this one.
I'd like something similar to this:
const [first, ...rest]: [first: Role, rest: Array<Role>] = this.employee.roles;
but it's not compiling.
Is there a clean way of typing this or should I just switch to
let first: Role;
let rest: Array<Role>;
[first, ...rest] = this.employee.roles;
CodePudding user response：
I would just use onst [first, ...rest]: Array<Role>. If you want you can type is with tuple types, but you will have to make first optional, since there is no guarantee Role[] will contain any elements, it could be empty:
const [first, ...rest]: [first?: Role, ...rest: Array<Role>] = roles;