js对象判断方法

// 判断对象的方法
let obj6 = { a: 1, b: 2 };
// 1. typeof
console.log(typeof obj6 === "object");
// 2. instanceof
console.log(obj6 instanceof Object === true);
// 3. constructor
console.log(obj6.constructor === Object);
// 4. Object.prototype.toString.call
console.log(Object.prototype.toString.call(obj) === "[object Object]");
// 5. __proto__
console.log(obj6.__proto__===Object.prototype);