Error while trying to destructure an array of possible length 2
You've not declared message
as an array; you've declared it as a tuple ([string]
) and tuples have a fixed number of elements. (See the Tuple section in the Basic Types documentation.)
You could declare it as a tuple that has two string elements ([string, string]
), but given that you are testing message.length >= 2
it seems likely you intended to declare it as a string array (string[]
):
let output = {status: false};if(execute.permission) { let message: string[] = execute.params; if(message.length >= 2) { // Destructuring follows [output['position'], output['message']] = message; }}
Use string[]
(an array of any length) instead of [string]
(a "tuple" limited to length 1) as your type.
Tuples have a specific length and make it easier to represent multiple types assigned to specific index positions, like [string, number]
. Homogenous (single-type) tuples are still useful in some scenarios (such as representing pairs in a map), but are not as common.
Arrays, on the other hand, are lists of variable length but are designed to hold only references of a single type (even if that type is a union type or any
). If one index of any array can hold a certain value, every index can hold that same kind of value.
TypeScript Code (Playground Link)
let execute = { permission: true, params: ['a', 'b']}let output = { status: false }; if(execute.permission) { let message: string[] = execute.params; if(message.length >= 2) { // Destructuring follows [output['position'], output['message']] = message; }}console.log(output)
Try to change type of message
variable. Array of strings suits better than array with single string
let message: string[] = execute.params;