Java作业

Example4_1

class XiyoujiRenwu{
    float height,weight;
    String head,ear;
    void speak(String s){
        System.out.println(s);
    }
}
public class Example4_1 {
    public static void main (String args[]){
        XiyoujiRenwu zhubajie,sunwukong;
        zhubajie = new XiyoujiRenwu();
        sunwukong = new XiyoujiRenwu();
    }
}

Example4_2

public class Examole4_2 {
    public static void main(String args[]){
        XiyoujiRenwu zhubajie = null,sunwukong = null;
        zhubajie=new XiyoujiRenwu();
        sunwukong=new XiyoujiRenwu();
        zhubajie.name=PersonName.八戒;
        zhubajie.height=1.83f;
        zhubajie.weight=86f;
        zhubajie.head="猪头";
        sunwukong.nasme=PersonName.悟空;
        sunwukong.height=1.66f;
        sunwukong.weight=1000f;
        sunwukong.head="猴头";
        System.out.println(zhubajie.name+"的身高:"+zhubajie.height);
        System.out.println(zhubajie.name+"的体重:"+zhubajie.weight);
        System.out.println(zhubajie.name+"的头:"+zhubajie.head);
        System.out.println(sunwukong.name+"的身高:"+sunwukong.height);
        System.out.println(sunwukong.name+"的体重:"+sunwukong.weight);
        System.out.println(sunwukong.name+"的头:"+sunwukong.head);
        zhubajie.speak(zhubajie.name+"我想娶媳妇");
        System.out.println(zhubajie.name+"现在的头:"+zhubajie.head);
        sunwukong.speak(sunwukong.name+"我重"+ sunwukong.weight+"公斤,想骗八戒背我");
        System.out.println(sunwukong.name+"现在的头:"+zhubajie.head);
    }
}

Example4_3

class Point{
    int x,y;
    void setXY(int m,int n){
        x = m;
        y = n;
    }
}
public class Example4_3 {
    public static void main(String args[]){
        Point p1,p2;
        p1 = new Point();
        p2 = new Point();
        System.out.println("p1的引用："+p1);
        System.out.println("p2的引用："+p2);
        p1.setXY(1111,2222);
        p2.setXY(-100,-200);
        System.out.println("p1的x,y坐标："+p1.x+","+p1.y);
        System.out.println("p2的x,y坐标："+p2.x+","+p2.y);
        p1 = p2;
        System.out.println("将p2的引用赋给p1后：");
        System.out.println("p1的引用："+p1);
        System.out.println("p2的引用："+p2);
        System.out.println("p1的x,y坐标："+p1.x+","+p1.y);
        System.out.println("p2的x,y坐标："+p2.x+","+p2.y);
    }
}

Example4_4

public class Example4_4 {
    public static void main(String args[]){
        Rect rect=new Rect();
        double w=12.76,h=25.28;
        rect.setWidth(w);
        rect.setHeight(h);
        System.out.println("矩形对象的宽："+rect.getWidth()+"高："+rect,getHeight());
        System.out.println("矩形的面积："+rect.getArea());
        System.out.println("更改向对象的方法参数传递值的w、h变量的值为100和256");
        w=100;
        h=256;
        System.out.println("矩形对象的宽："+rect.getWidth()+"高："+rect.getHeight());
    }
}

Example4_6

public class Example4_6 {
    public static void main(String args[]){
        Computer computer=new Computer();
        double result=computer.getResult(1.0/3,10,20,30);
        System.out.println("10,20,30的平均数："+result);
        result=computer.getResult(1.0/6,66,12,5,89,2,51);
        System.out.println("66,12,5,89,2,51的平均数:"+result);
    }
}

Example4_8

public class Example4_8 {
    public static void main(String args[]){
        Ladder.下底=100;
        Ladder ladderOne = new Ladder();
        Ladder ladderTwo = new Ladder();
        ladderOne.设置上底(28);
        ladderTwo.设置上底(66);
        System.out.println("ladderOne的上底:"+ladderOne.获取上底());
        System.out.println("ladderOne的下底:"+ladderOne.获取下底());
        System.out.println("ladderTwo的上底:"+ladderTwo.获取上底());
        System.out.println("ladderTwo的下底:"+ladderTwo.获取下底());
    }
}

Example4_9

class A{
    int x,y,z;
    static int getContinueSum(int start,int end){
        int sum=0;
        for (int i=start;i<=end;i++){
            sum=sum+i;
        }
        return sum;
    }
}
public class Example4_9 {
    public static void main(String args[]){
        int result=A.getContinueSum(0,100);
        System.out.println(result);
    }
}

Example4_10

package tom.jiafei;
public class Example4_10 {
    public static void main(String args[]){
        Student stu=new Student(10201);
        stu.speak();
        System.out.println("主类的包名也是tom.jiafei");
    }
}

Example4_16

lass AAA{
    private int money;
    private int getMoney(){
        return money;
    }
}
class E{
    public static void main(String args[]){
        AAA exa=new AAA();
        exa.money=3000;
        int m=exa.getMoney();
        System.out.println("money="+m);
    }
}

Example4_17

public class Example4_17 {
    public static void main(String args[]){
        Student zhang=new Student();
        Student geng=new Student();
        zhang.setAge(23);
        System.out.println("zhang的年龄:"+zhang.getAge());
        geng.setAge(25);
        //"zhang.age=23;或"geng.age=25;"都是非法的，因为zhang和geng已经不在Student类中
        System.out.println("geng的年龄："+geng.getAge());
    }
}

习题5_1

class AAA{
    static int m ;
    static {
        m = 888;
    }
}
public class E{
    public static void main(String args[]){
        AAA a= null;
        System.out.println("%d:%d",AAA.m,a.m);
    }
}

习题5_2

class CPU{
    int speed;
    int getSpeed(){
        return speed;
    }
    public void setSpeed(int speed){
        this.speed=speed;
    }
}
class HardDisk{
    int amount;

    public int getAmount() {
        return amount;
    }
    public void setAmount(int amount){
        this.amount=amount;
    }
}
class PC{
    CPU cpu;
    HardDisk HD;
    void setCpu(CPU cpu){
        this.cpu=cpu;
    }
    void setHardDisk(HardDisk HD){
        this.HD=HD;
    }
    void show(){
        System.out.println("CPU速度："+cpu.getSpeed());
        System.out.println("硬盘容量："+HD.getAmount());
    }
}
class  Test{
    public static void main(String args[]){
        CPU cpu=new CPU();
        HardDisk HD=new HardDisk();
        cpu.getSpeed(2200);
        HD.setAmount(200);
        PC pc=new PC();
        pc.setCpu(cpu);
        pc.setHardDisk(HD);
        pc.show();
    }
}