Types when destructuring arrays

Question

function f([a,b,c]) {   // this works but a,b and c are any } 

it's possible write something like that?

function f([a: number,b: number,c: number]) {   // being a, b and c typed as number  } 

Answer 1

This is the proper syntax for destructuring an array inside an argument list:

function f([a,b,c]: [number, number, number]) {  } 

Answer 2

Yes, it is. In TypeScript, you do it with types of array in a simple way, creating tuples.

type StringKeyValuePair = [string, string]; 

You can do what you want by naming the array:

function f(xs: [number, number, number]) {} 

But you wouldn't name the interal parameter. Another possibility is use destructuring by pairs:

function f([a,b,c]: [number, number, number]) {}