构造器重载 运行后的结果不正确

Question

构造器重载

敲完程序后 运行的结果不正确 不晓得是哪里出现了问题
请各位朋友帮忙

Answer 1

public static void main(String[] args){
        Animal a1 = new Animal();
        System.out.println("--------");
        Animal a2 = new Animal(18);
        System.out.println("--------");
        Animal a3 = new Animal("Tony");
        System.out.println("--------");
        Animal a4 = new Animal("Jerry",22);
        System.out.println("--------");
    }