类型检测-instanceof

  let arr = [1, 2, 3, 4]
        // 判断arr是否属于某个类
        console.log(arr instanceof Array);//判断是否属于数组类  返回值：true
        console.log(arr instanceof Object);//判断是否属于引用类 返回值： true

        let obj = {}
        console.log(obj instanceof Array);//判断是否为数组类 返回值：false
        console.log(obj instanceof Object);//判断是否为引用类 返回值：true

        //检测构造函数
        function Person(color, like) {
            this.color = color;
            this.link = like;
        }
        let p1 = new Person("#ff0000", "旅游")
        console.log(p1 instanceof Person); //判断p1是否属于Person类 返回值：true
        console.log(p1 instanceof Function); //判断p1是否属于Function类 返回值：false