問題
var obj = {}
Object.getPrototypeOf(obj); //=> Object {__defineGetter__: function, ~省略~}
'toString' in obj; //=> true
var obj = Object.create(null);
Object.getPrototypeOf(obj); //=> ?
'toString' in obj; //=> ?
答え
var obj = {}
Object.getPrototypeOf(obj); //=> Object {__defineGetter__: function, ~省略~}
'toString' in obj; //=> true
var obj = Object.create(null);
Object.getPrototypeOf(obj); //=> null
'toString' in obj; //=> false
creteで{}作りたいなら、
var obj = Object.create(Object.prototype);
Object.getPrototypeOf(obj); //=> Object {__defineGetter__: function, ~省略~}
'toString' in obj; //=> true