Array destructuring in parameters list, with TypeScript

Question

Using TypeScript, I am trying to figure out how to do array destructuring in the arguments list.

We can use object destructuring like so:

let foo = function({firstname, lastname}){...}

foo({
  firstname: 'ralph',
  lastname: 'lauren'
});

I am wondering if we can do the same thing with array destructuring, it would be very useful for me, something like:

let bar = function([desc, opts, fn]){...}

bar([
  'yes',
   {},
   function(){}
]);

is it possible to do this with an array with TypeScript?

Of course it is possible, why would it not? Haven't you tried it? It works since ES6. — Bergi
– Bergi, Commented Jun 22, 2017 at 0:44
what is this called, so I google how to do it with TypeScript — Alexander Mills
– Alexander Mills, Commented Jun 22, 2017 at 0:45
Maybe you should make it a TypeScript question then and post the error message you got from the compiler. I guess the type checker doesn't like it, similar to the problem with spread arguments? — Bergi
– Bergi, Commented Jun 22, 2017 at 0:46

Jokester · Accepted Answer · 2017-06-22 01:12:33Z

33

An array of fixed length and types is also called a tuple in TS. We can destructure a tuple argument like:

let bar = function ([desc, opts, fn]: [string, {}, Function]) {


}

bar([
    'yes',
    {},
    function () { }
]);

answered Jun 22, 2017 at 1:12

Jokester

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1 Comment

What about an arbitrary length array? or destructuring the first few elements and collecting the remainder with the spread operator?