Java期末复习练习题2014版

J=100;

Systerm.out.println(“j=”+j); }

Public static void main (String[] args){

Systerm.out.println(“InitDemo.j=”InitDemo.j”); InitDemo aa=new InitDemo(); InitDemo.j=500;

Systerm.out.println(“aa.j=”+aa.j); }}

答：j = 100

InitDemo.j = 100 i = 5 j = 10 j = 1000 aa.j = 500

32．

class Animal{

public Animal（）{

System.out.println(“I’m an animal”); } }

class Bird extends Animal{ public Bird(){

System.out.println(“I’m a bird.”); } }

public class AnimalTest{

public static void main(String[]args){ Bird b = new Bird(); } }

运行结果为： I'm an animal I'm a bird.

33． class A{ int x,y;

void setXY(int x,int y){ this.x = x; this.y = y; }

int multiply(){ return x * y; } }

class B extends A{ int x,z;

B(int x,int z){

super(); this.x =x; this.z =z; }

int multiply(){ return x * y * z; } }

public class ABTest{

public static void main(String[]args){ A a = new B(5,10);//x=5,z=10 a.setXY(10,20);//x=10,y=20

System.out.println(\ B b=new B(6,9);//x=6.z=9 b.setXY(7,8);//x=7,y=8 b.z=10;//z=10

System.out.println(\ } }

运行结果为： m=1000 m=480

34．class Parent{ void printMe(){

System.out.println(\ } }

class Child extends Parent{ void printMe(){

System.out.println(\}

void printAll(){ super.printMe(); this.printMe(); printMe(); } }

public class Test{

public static void main(String[]args){ Child myC = new Child(); myC.printAll(); } }

运行结果为： I'm a parent. I'm a child. I'm a child.

Press any key to continue... 34．

abstract class AA{

abstract void callme(); void metoo(){

System.out.println(\ } }

class BB extends AA{ void metoo(){

System.out.println(\ }

void callme(){

System.out.println(\ } }

public class AbstractTest{

public static void main(String[]args){ AA aa = new BB(); aa.callme(); aa.metoo(); } }

运行结果：

Inside BB's callme. Inside BB's metoo.

Press any key to continue... 35．

class Employee{}

class Manager extends Employee{} class Secretary extends Employee{} class Programmer extends Employee{} public class Test24{ public static void method(Employee e){ if (e instanceof Manager) System.out.println(\ else if (e instanceof Secretary) System.out.println(\else if (e instanceof Programmer) System.out.println(\ }

public static void main(String[] args){ Manager m = new Manager(); Secretary s = new Secretary(); Programmer p = new Programmer(); method(m); method(s); method(p); } }

输出结果为：

He is a Manager. He is a Secretary. He is a Programmer.

36．

public class Test{

public static void main(String [] args){ try{

for(int i = 3 ; i >= 0 ; i--){

System.out.println(\System.out.println(6 / i); }

}catch(ArithmeticException ae){ System.out.println(\ } }

}

输出结果为：

The value of i : 3 2

The value of i : 2 3

The value of i : 1 6

The value of i : 0 Divided by zero. 37．

public class Foo{ public static void method(int i){ try{ if(i >0){ return; }else{ System.exit(1); } } finally{ System.out.println(\ }

public static void main(String [] args){ method(5); method(-5); } }

输出结果为：

Finally

38．

public class Test1{

public static String output=\public static void foo(int i){ try {

if(i==1){

throw new Exception(); }

output +=\

}catch (Exception e){ output +=\return ; }finally{

output +=\}

output +=\}

public static void main(String[] args){ foo(0); foo(1);

System.out.println(\