都会返回类型信息，但installedof与内存中的比较typeof与字符串比较

//objects  var Person = function() {}  var gary = new Person();  console.log(typeof(gary)); // "object"  gary instanceof Person // true  //literals  var str = 'hello world';  console.log(typeof(str)); // "string"  str instanceof String // False  var str1 = new String('hello world');  console.log(typeof(str1)) // "object"  str1 instanceof String // true