let x, { x: y = 1 } = { x }; y;
[...[...'...']].length
typeof (new (class F extends (String, Array) { })).substring
let some_text = "some string";
if(some_text.indexOf('str') !=-1){
return true;
}
let point = [1,3], segment = [point,[5,5]], triangle = [...segment,[1,8]];
const [a, , b] = [1, 2, 3];
console.log(a, b);