第九周上机作业
1、定义一个点类Point,包含2个成员变量x、y分 别表示x和y坐标,2个构造器Point()和Point(int x0,y0),以及一个movePoint(int dx,int dy)方法实 现点的位置移动,创建两个Point对象p1、p2,分 别调用movePoint方法后,打印p1和p2的坐标。 package kksk; public class kksk { public static void main(String[] args) { point p1=new point(1,2); point p2=new point(1,2); System.out.println("p1坐标为"+"("+p1.getX()+","+p1.getY()+")"); System.out.println("p2坐标为"+"("+p2.getX()+","+p2.getY()+")"); p1.movePoint(2,3); p2.movePoint(3,4); System.out.println("p1坐标为"+"("+p1.getX()+","+p1.getY()+")"); System.out.println("p2坐标为"+"("+p2.getX()+","+p2.getY()+")"); } } public class point { private int x; private int y; public point() { } public point(int x, int y) { this.x = x; this.y = y; } public void movePoint(int x, int y){ this.x=x; this.y=y; } public int getX() { return x; } public void setX(int x) { this.x = x; } public int getY() { return y; } public void setY(int y) { this.y = y; } } 2、定义一个矩形类Rectangle:(知识点:对象的 创建和使用) • 2.1 定义三个方法:getArea()求面积、getPer()求 周长,showAll()分别在控制台输出长、宽、面积 、周长。 • 2.2 有2个属性:长length、宽width • 2.3 通过构造方法Rectangle(int width, int length), 分别给两个属性赋值 • 2.4 创建一个Rectangle对象,并输出相关信息 package method; public class Rectangle { double length; double width; public Rectangle(double length,double width){ this.length=length; this.width=width; } public double getArea(double length,double width){ return this.length*this.width; } public double getPer(double length,double width){ return 2*(this.length+this.width); } public void showAll(double length,double width){ System.out.printf("长方形的长为:%3.3f,宽为:%3.3f\n",this.length,this.width); System.out.printf("长方形的面积为:%3.3f\n",getArea(length,width)); System.out.printf("长方形的周长为:%3.3f\n",getPer(length,width)); } public static void main(String[] args) { // TODO Auto-generated method stub Rectangle rectangle=new Rectangle(4,5); rectangle.showAll(rectangle.length,rectangle.width); } } • 3、定义一个笔记本类,该类有颜色(char)和cpu 型号(int)两个属性。 • 3.1 无参和有参的两个构造方法;有参构造方法可 以在创建对象的同时为每个属性赋值; • 3.2 输出笔记本信息的方法 • 3.3 然后编写一个测试类,测试笔记本类的各个 方法。 package chap3; public class bijiben { public String name; char color; int xinghao; public void getDate() { } public void getDate(char color, int xinghao) { this.color = color; this.xinghao = xinghao; } public void showAll() { System.out.println(name + "颜色为" + color + "型号" + xinghao); } } package chap3; public class Person { public static void main(String[] args) { bijiben rc = new bijiben(); rc.name = "笔记本"; rc.getDate('a', 7); rc.showAll(); } } 6、定义两个类,描述如下: • 6.1定义一个人类Person: • 6.1.1定义一个方法sayHello(),可以向对方发出 问候语“hello,my name is XXX” • 6.1.2有三个属性:名字、身高、年龄 • 6.1.3通过构造方法,分别给三个属性赋值 • 6.2定义一个Constructor类: • 6.2.1创建两个对象,分别是zhangsan,33岁, 1.73;lishi,44,1.74 • 6.2.2分别调用对象的sayHello()方法。 package hp; public class Person { String name; double height; int age; public void sayHello(){ System.out.println("hello,my name is " + this.name ); } public void Value(String name, int age, double height){ this.name = name; this.age = age; this.height = height; } } package hp; public class Constructor { public static void main(String[] args) { // TODO Auto-generated method stub Person p1 = new Person(); p1.Value("zhangsan",33,1.74); p1.sayHello(); Person p2 = new Person(); p2.Value("lishi",44,1.74); p2.sayHello(); } }