SOURCE

class subject {
    constructor(name){
        this.name=name,
        this.state="开心"
    }
}

class observer{
    constructor(name){
      this.name=name
    }
}

var baby=new subject("宝宝")
var father=new subject("爸爸")
var monther=new subject("妈妈")

console.log(baby)