Concatenate array if is not undefined

Question

I´m concatenate two different arrays into one,

let myarray = [...myarray1, ...myarray2];

If myarray2 is undefined how can I make this concatenation in the best way?

 if(myarray2){
         let myarray = [...myarray1, ...myarray2];
    }

This is too ugly INMHO. Could i not do something like:

let myarray = [...myarray1, ...?myarray2];

Answer 1

You may use this syntax

let myarray = [...(myarray1 ?? []), ...(myarray2 ?? [])];