- class Poly{
- public static void main(String[] args) {
- Man man = new SuperMan();
- System.out.println(man.name);
- man.doJob();
- //因为编译看左边,栈中定义的变量无法找到Man类型地址,所以子类新增的类,无法调用
- //man.saveMan();
- SuperMan sm = (SuperMan)man;
- sm.saveMan();
- }
- }
- class SuperMan extends Man {
- String name = "SuperMan";
- void doJob() {
- System.out.println("谈大生意");
- }
- void saveMan() {
- System.out.println("救人");
- }
- }
- class Man {
- String name = "john";
- void doJob() {
- System.out.println("谈生意");
- }
- }
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