ts版本：

class Animal{

    fullStr:string;

    constructor(public color,public size,public age){

        this.fullStr=color+' '+size+' '+age

    }

}

let cat=new Animal("red","1KG","2")

js版本

let Animal =( function(){

            function Animal(color,size,age){

                this.color=color;

                this.size=size;

                this.age=age;

                this.fullStr=color+' '+size+' '+age;

            }

             return Animal;

}())

let cat=new Animal("red","1KG","2")