(function() {
    class Animal {
        name:string;
        constructor(name:string) {
            this.name = name;
        }
    }
    class B extends Animal {
        age: number;
        constructor(name:string,age:number) {
            super(name)
            this.age = age;
        }  
    }

    let b = new B("图图",3)
    console.log(b)
})()