关于前端:js笔试题

那个是正确的

1.for (let index = 0; index < 12; index++) {};console.log(index);//谬误
2.const a = 12;a = 13;console.log(a);//谬误
3.const G = {a:3};console.log(G.a);G.b=12;console.log(G.b);// 3,12
4.let [head,...tail] = [1,2,3,4];console.log(tail)// [2,3,4]

请问输入的是 // GoodByeJack

var name = 'world';
(function () {
 var name;
 if (typeof name === "undefined") {
     name = 'Jack';
     console.log('GoodBye'+name)
 } else {
     console.log('hello'+name)
 }
})();