java的第3次作业
1.编写一个Java应用程序,该程序包括3个类:Monkey类、People类和主类E。要求:
(1) Monkey类中有个构造方法:Monkey (String s),并且有个public void speak()方法,在speak方法中输出“咿咿呀呀......”的信息。
(2)People类是Monkey类的子类,在People类中重写方法speak(),在speak方法中输出“小样的,不错嘛!会说话了!”的信息。
(3)在People类中新增方法void think(),在think方法中输出“别说话!认真思考!”的信息。
(4)在主类E的main方法中创建Monkey与People类的对象类测试这2个类的功能。
1 package LHB.inherit; 2 import java.util.*; 3 class Monkey 4 { String s; 5 public Monkey(String s) 6 { 7 this.s=s; 8 } 9 public void speak() 10 { 11 System.out.println("好嗨哟!"); 12 } 13 } 14 class People extends Monkey 15 { 16 public People(String s) { 17 super(s); 18 } 19 public void speak() 20 { 21 System.out.println("感觉人生已经到达了巅峰"); 22 } 23 public void think() 24 { 25 System.out.println("你好牛哦,你才是真正的大人物"); 26 } 27 28 } 29 public class E 30 { 31 public static void main(String[] args) 32 { 33 Scanner in=new Scanner(System.in); 34 String s; 35 s=in.next(); 36 Monkey p=new Monkey(s); 37 People q=new People(s); 38 p.speak(); 39 q.speak(); 40 q.think(); 41 } 42 43 }
2.按要求编写一个Java应用程序:
(1)定义一个类,描述一个矩形,包含有长、宽两种属性,和计算面积方法。
(2)编写一个类,继承自矩形类,同时该类描述长方体,具有长、宽、高属性,和计算体积的方法。
(3)编写一个测试类,对以上两个类进行测试,创建一个长方体,定义其长、宽、高,输出其底面积和体积。
1 package LHB.inherit; 2 import java.util.*; 3 class Rectangle 4 { 5 int length,width; 6 public int area(int length,int width)/*矩形面积*/ 7 { 8 this.length=length; 9 this.width=width; 10 int s; 11 s=length*width; 12 return s; 13 } 14 } 15 class Cuboid extends Rectangle 16 { 17 int length,width,heigth; 18 public Cuboid(int length,int width,int heigth) 19 { 20 this.length=length; 21 this.width=width; 22 this.heigth=heigth; 23 } 24 public int area()/*长方体底面积*/ 25 { 26 int s; 27 s=length*width; 28 return s; 29 } 30 public int Volume()/*长方体体积*/ 31 { 32 int v; 33 v=area()*heigth; 34 return v; 35 } 36 37 } 38 public class Test 39 { 40 41 public static void main(String[] args) 42 { 43 int length,width,heigth; 44 Scanner in=new Scanner(System.in); 45 System.out.print("请输入长宽高:"); 46 length=in.nextInt(); 47 width=in.nextInt(); 48 heigth=in.nextInt(); 49 Rectangle p=new Rectangle(); 50 Cuboid q=new Cuboid(length,width,heigth); 51 System.out.println("矩形的面积是:"+p.area(length, width)); 52 System.out.println("长方体的体积是:"+q.Volume()); 53 54 } 55 56 }
3.编写一个Java应用程序,设计一个汽车类Vehicle,包含的属性有车轮个数wheels和车重weight。小车类Car是Vehicle的子类,其中包含的属性有载人数loader。卡车类Truck是Car类的子类,其中包含的属性有载重量payload。每个类都有构造方法和输出相关数据的方法。最后,写一个测试类来测试这些类的功能。
1 package LHB.inherit; 2 import java.util.*; 3 class Vehicle 4 { 5 int wheels,weight;/*车轮个数,车重*/ 6 public Vehicle(int wheels,int weight) 7 { 8 this.wheels=wheels; 9 this.weight=weight; 10 } 11 public void print() 12 { 13 System.out.println("车轮个数是:"+wheels+"个\n"+"车重是:"+weight); 14 } 15 } 16 class Car extends Vehicle 17 { 18 int loader;/*车载人数*/ 19 public Car(int wheels, int weight,int loader) 20 { 21 super(wheels, weight); 22 this.loader=loader; 23 } 24 public void print() 25 { 26 System.out.println("车载人数是:"+loader); 27 } 28 } 29 class Truck extends Car 30 { 31 int payload;/*载重量*/ 32 public Truck(int wheels, int weight, int loader,int payload) 33 { 34 super(wheels, weight, loader); 35 this.payload=payload; 36 } 37 public void print() 38 { 39 System.out.println("载重量是:"+payload); 40 } 41 } 42 public class Testcar 43 { 44 45 public static void main(String[] args) 46 { 47 Scanner in=new Scanner(System.in); 48 int wheels,weight,loader,payload; 49 System.out.print("请输入车轮个数,车重,车载人数,载重量:"); 50 wheels=in.nextInt(); 51 weight=in.nextInt(); 52 loader=in.nextInt(); 53 payload=in.nextInt(); 54 Vehicle p1=new Vehicle(wheels,weight); 55 Car p2=new Car(wheels,weight,loader); 56 Truck p3=new Truck(wheels,weight,loader,payload); 57 p1.print(); 58 p2.print(); 59 p3.print(); 60 } 61 62 }