java程序设计基础_陈国君版第五版_第八章例题
class Person{
private String name;
private int age;
public Person(){
System.out.println("调用了个人类的构造方法Person()");
}
public void setNameAge(String name , int age)
{
this.name = name ;
this.age = age ;
}
public void show()
{
System.out.println("姓名："+name+"\t年龄："+age);
}
}
class Student extends Person{
private String department;
public Student()
{
System.out.println("调用了学生类的构造方法Student()");
}
public void setDepartment(String dep)
{
department =dep;
System.out.println("我是"+department+"的学生");
}
}
public class Main8_1 {
public static void main(String[] args)
{
Student stu =new Student();
stu.setNameAge("张三",21);
stu.show();
stu.setDepartment("计算机系");
}
}
class Person2{
private String name;
private int age;
public Person2(){
System.out.println("调用了个人类的无参构造方法Person()");
}
public Person2(String name,int age){
System.out.println("调用了个人类的有参构造方法");
this.name =name;
this.age = age;
}
public void show()
{
System.out.println("姓名："+name+"\t年龄："+age);
}
}
class Student2 extends Person2{
private String department;
public Student2()
{
System.out.println("调用了学生类的无参构造方法Student()");
}
public Student2(String name , int age ,String dep)
{
super(name,age);
department = dep;
System.out.println("我是"+department + "的学生");
System.out.println("调用了学生类的有参构造方法Student(String name,int age ,String dep)");
}
}
public class Main8_2 {
public static void main(String[] args)
{
Student2 stu =new Student2();
Student2 stu2 =new Student2("李四",23,"信息系");
stu.show();
stu2.show();
}
}
class Person3
{
protected String name ;
protected int age ;
public Person3()
{
}
public Person3(String name,int age)
{
this.name = name;
this.age = age;
}
protected void show()
{
System.out.println("姓名："+name+"\t年龄："+age);
}
}
class Student3 extends Person3{
private String department;
int age = 20;
public Student3 (String xm,String dep)
{
name = xm ;
department = dep;
super.age = 25;
System.out.println("子类Student中的成员变量 age ="+age);
super.show();
System.out.println("系别："+department);
}
}
public class Main8_3 {
public static void main(String[] args){
Student3 stu = new Student3("李四","信息系");
}
}
class Person4
{
protected String name ;
protected int age ;
public Person4(String name,int age)
{
this.name = name;
this.age = age;
}
protected void show()
{
System.out.println("姓名："+name+"\t年龄："+age);
}
}
class Student4 extends Person4{
private String department;
public Student4(String name , int age ,String dep)
{
super(name,age);
department = dep;
}
protected void show()
{
System.out.println("系别："+department);
}
}
public class Main8_4 {
public static void main(String[] args)
{
Student4 stu = new Student4("老王",24,"电子");
stu.show();
}
}
class Person5
{
protected String name ;
protected int age ;
public Person5(String name,int age)
{
this.name = name;
this.age = age;
}
protected void show()
{
System.out.println("姓名："+name+"\t年龄："+age);
}
}
class Student5 extends Person5{
private String department;
public Student5(String name , int age ,String dep)
{
super(name,age);
department = dep;
}
protected void show()
{
System.out.println("系别："+department);
}
public void subShow()
{
System.out.println("我在子类中");
}
}
public class Main8_5 {
public static void main(String[] args)
{
Person5 per = new Student5("王涛",24,"电子");
per.show();
//per.subshow();
}
}
class AAA
{
static final double PI = 3.14;
public final void show()
{
System.out.println("pi = "+PI);
}
}
class BBB extends AAA
{
private int num = 100;
/*public void show()
{
System.out.println("num = "+ num);
}*/
}
public class Main8_6 {
public static void main(String[] args){
BBB ex = new BBB();
ex.show();
}
}
class A
{
int a = 1;
}
public class Main8_7 {
public static void main(String[] args){
A obj1 = new A();
A obj2 = new A();
String s1,s2,s3 = "abc",s4 = "abc";
s1 = new String("abc");
s2 = new String("abc");
System.out.println("s1.eauqls(s2)是"+(s1.equals(s2)));
System.out.println("s1 == s3是"+(s1 == s3));
System.out.println("s1.equals(s3)是"+(s1.equals(s3)));
System.out.println("s3 == s4是"+(s3 == s4));
System.out.println("s2.equals(s3)是"+(s2.equals(s3)));
System.out.println("s1==s2是"+(s1 == s2));
System.out.println("obj1 == obj2是"+(obj1 == obj2));
System.out.println("obj1.equals(obj2)是"+(obj1.equals(obj2)));
obj1 = obj2;
System.out.println("obj1 = obj2后obj1 == obj2是"+(obj1==obj2));
System.out.println("obj1 = obj2 后 obj1.equals(obj2) 是"+(obj1.equals(obj2)));
}
}
class Person1
{
protected String name;
public Person1(String xm)
{
name = xm;
}
}
public class Main8_8 {
public static void main(String [] args)
{
Person1 per = new Person1("张三");
Class obj = per.getClass();
System.out.println("对象per 所属的类为:"+obj);
System.out.println("对象per是否是接口："+obj.isInterface());
}
}
public class Main8_9
{
static int count = 0;
protected String name;
protected int age;
public Main8_9(String n1,int a1)
{
name = n1;
age = a1;
this.count++;
}
public String toString()
{
return this.name+" , "+this.age;
}
public void display()
{
System.out.print("本类名 = "+this.getClass().getName()+";");
System.out.println("父类名 = "+this.getClass().getSuperclass().getName());
System.out.print("Main8_9.count = "+this.count+" ");
System.out.print("Student9.count = "+Student9.count+" ");
Object obj = this;
if(obj instanceof Student9)
System.out.println(obj.toString() + "是Student9类对象");
else if(obj instanceof Main8_9)
System.out.println(obj.toString() + "是Main8_9类对象");
}
}
class Student9 extends Main8_9
{
static int count = 0;
protected String dept;
protected Student9(String n1,int a1,String d1)
{
super(n1,a1);
dept = d1;
this.count++;
}
public String toString()
{
return super.toString() +","+dept;
}
public void display()
{
super.display();
System.out.print("super.count = "+super.count);
System.out.println("\t;this.count="+this.count);
}
public static void main(String[] args){
Main8_9 per = new Main8_9("王永涛",23);
per.display();
Student9 stu = new Student9("张小三",22,"计算机系");
stu.display();
}
}
abstract class Shape
{
protected String name;
public Shape(String xm)
{
name = xm;
System.out.print("名称:"+name);
}
abstract public double getArea();
abstract public double getLength();
}
class Circle extends Shape
{
private final double PI = 3.14;
private double radius;
public Circle(String shapeName,double r)
{
super(shapeName);
radius = r;
}
public double getArea()
{
return PI*radius*radius;
}
public double getLength()
{
return 2*PI*radius;
}
}
class Rectangle extends Shape
{
private double width;
private double height;
public Rectangle(String shapeName,double width,double height)
{
super(shapeName);
this.width = width;
this.height = height;
}
public double getArea()
{
return width * height;
}
public double getLength()
{
return 2*(width*height);
}
}
public class Main8_10 {
public static void main(String[] args){
Shape rect = new Rectangle("长方形",6.5,10.3);
System.out.print(";面积 = "+rect.getArea());
System.out.println(";周长 ="+rect.getLength());
Shape circle = new Circle("圆",10.2);
System.out.println(";面积 = "+circle.getArea());
System.out.println(";周长= "+circle.getLength());
}
}
interface IShape
{
final double PI = 3.14;
abstract double getArea();
abstract double getLength();
}
class Circle_11 implements IShape
{
double radius;
public Circle_11(double r)
{
radius = r;
}
public double getArea()
{
return PI*radius*radius;
}
public double getLength()
{
return 2*PI*radius;
}
}
class Rectangle_11 implements IShape
{
private double width;
private double height;
public Rectangle_11(double width,double height)
{
this.width = width;
this.height = height;
}
public double getArea()
{
return width * height;
}
public double getLength()
{
return 2*(width + height);
}
}
public class Main8_11 {
public static void main(String[] args){
IShape Circle_11 = new Circle_11(5.0);
System.out.print("圆面积 ="+Circle_11.getArea());
System.out.println(";周长 = "+Circle_11.getLength());
Rectangle_11 rect = new Rectangle_11(6.5,10.8);
System.out.print("矩形面积 ="+rect.getArea());
System.out.println(";周长 = "+rect.getLength());
}
}
interface Face1
{
final double PI = 3.14;
abstract double area();
}
interface Face2
{
abstract void setColor(String c);
}
interface Face3 extends Face1,Face2
{
abstract void volume();
}
public class Main8_12 implements Face3 {
private double radius;
private int height;
protected String color ;
public Main8_12(double r,int h)
{
radius = r;
height = h;
}
public double area()
{
return PI*radius*radius;
}
public void setColor(String c)
{
color = c;
System.out.println("颜色："+color);
}
public void volume(){
System.out.println("圆柱体体积 ="+area()*height);
}
public static void main(String[] args){
Main8_12 volu = new Main8_12(3.0,2);
volu.setColor("红色");
volu.volume();
}
}
interface Face1_13
{
final double PI = 3.14;
abstract double area();
}
interface Face2_13
{
abstract void volume();
}
public class Main8_13 implements Face1_13,Face2_13{
private double radius;
private int height;
public Main8_13(double r,int h)
{
radius = r;
height = h;
}
public double area()
{
return PI*radius*radius;
}
public void volume()
{
System.out.println("圆柱体体积 ="+area()*height);
}
public static void main(String[] args){
Main8_13 volu = new Main8_13(5.0,2);
volu.volume();
}
}
public class Main8_14 {
private int age;
public class Student
{
String name;
public Student(String n,int a)
{
name = n;
age = a;
}
public void output(){
System.out.println("姓名："+this.name+";年龄："+age);
}
}
public void output()
{
Student stu = new Student("刘洋",24);
stu.output();
}
public static void main(String[] args){
Main8_14 g = new Main8_14();
g.output();
}
}
public class Main8_15 {
public static void main(String[] args){
(
new Inner()
{
void setName(String n)
{
name = n;
System.out.println("姓名："+name);
}
}
).setName("张 华");
}
static class Inner
{
String name;
}
}
本篇博客详细探讨了《java程序设计基础》陈国君版第五版第八章的例题，涵盖了Java类（class）的使用、字符串操作以及编程设计实践。
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