function Person(){
};
var person = new Person();
function Student(){};
Student.prototype = new Person();
console.log(Student.prototype)
Student.prototype.construstor = Student;
console.log(Student)
console.log(Object.prototype.toString.apply([1,2])=="[object Array]")
console.log(Object.prototype.toString.apply(function(){})=="[object Function]")
console.log(Object.prototype.toString.apply([1,2])=="[object Array]")
// typeof比较适合基本类型的检测 遇到null 会返回 object
console.log(typeof('123'))
console.log(typeof(123))
console.log(typeof(null))
console.log(typeof(function(){}))
//左操作数是对象 右边必须是函数对象或者函数构造器
console.log([1,2,3] instanceof Array)
console.log(person instanceof Person)