43.请阅读下面的程序,写出程序的运行结果。 class Person { String name; int age; public Person() { } public Person(String n) { name = n; } public Person(String n, int a) { name = n; age = a; } public void show() { System.out.println(name + “---“ + age); } } public class Test { public static void main(String[] args) { Person p1 = new Person(); Person p2 = new Person(“”); Person p3 = new Person(“”, 27); p1.show(); p2.show(); p3.show(); } }