如何在ES6中判断类中是否包含某个属性和方法

1、应用方法

      hasOwnProperty

2、应用实例

class Student{
	constructor(sno,sname,sage,ssex) {
	    this.sno = sno;
	    this.sname = sname;
	    this.sage = sage;
	    this.ssex = ssex;
	}
	
	toString(){
		return '学号：' + this.sno + ',姓名：' + this.sname + ',年龄：' + this.sage + ',性别：' + this.ssex;
	}
}

let s = new Student('1','张思',20,'女');
let info = s.toString();
console.log(info);
let name = s.hasOwnProperty('sname');
let age = s.hasOwnProperty('age');
let sex = s.hasOwnProperty('sex');
console.log(name,age,sex);
let to = s.hasOwnProperty('toString');
console.log(to);
let tos = s.__proto__.hasOwnProperty('toString');
console.log(tos);

3、运行结果

学号：1,姓名：张思,年龄：20,性别：女
true false false
false
true