以下代码调试结果 class Base {} class Sub extends Base {} public class CEx{ public static void main(String argv[]){ Base b = new Base(); Sub s = (Sub) b; } }
举一反三
- 如何能使程序调用Base类的构造方法输出"base constructor"; class Base{ Base(int i){ System.out.println("base constructor"); } Base(){ } } public class Sup extends Base{ public static void main(String argv[]){ Sup s= new Sup(); //One } Sup() { //Two } public void derived() { //Three } }
- 以下代码调试结果 class Base {} class Sub extends...Sub s = (Sub) b; } }
- 选择下面程序运行的结果，并说明原因class Base{Base(){System.out.println("Base");}}public class Checket extends Base{Checket(){System.out.println("Checket");super();}public static void main(String[] arg){Checket c = new Checket();}}
- 当你编译运行下列程序代码,会得到什么结果? 。 private class Base{ Base(){ int i = 100; System.out.println(i); } } public class Pri extends Base{ static int i = 200; public static void main(String argv[]){ Pri p = new Pri(); System.out.println(i); } }
- 对于一下程序，其运行结果为 class Base{ public Base(){ System.out.print("C"); } } class Base2 extends Base{ public Base2(){ System.out.print("B"); } } public class TestDemo extends Base2{ int m=1; public TestDemo(){ System.out.println("A"); } public static void main(String args[]){ TestDemo t = new TestDemo(); } }