第九周练习
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。[
必作题]
class text1{ 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)[必做题]
• 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
import java.util.Scanner; //测试类 class text2{ public static void main(String[] args) { Rectangle r=new Rectangle(); System.out.println("请输入矩形长度"); Scanner sc=new Scanner(System.in); int length = sc.nextInt(); r.setLength(length); System.out.println("请输入矩形宽度"); int width = sc.nextInt(); r.setWidth(width); r.getAll(); r.getArea(); r.getPer(); } } //矩形类 public class Rectangle { private int length; private int width; public Rectangle() { } public Rectangle(int length, int width) { this.length = length; this.width = width; } public int getLength(int i) { return length; } public int getWidth() { return width; } public void setLength(int length) { this.length = length; } public void setWidth(int width) { this.width = width; } //求面积 public void getArea(){ System.out.println("面积为;"+width*length); } //求周长 public void getPer(){ System.out.println("周长为;"+(width+length)*2); } public void getAll(){ System.out.println("长度为"+length+"宽度为"+width+"面积为"+width*length+"周长为"+(width+length)*2); } }
• 3、定义一个笔记本类,该类有颜色(char)和cpu
型号(int)两个属性。 [必做题]
• 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。
class text3{ public static void main(String[] args) { NoteBookComputer nbc=new NoteBookComputer('黑',1080); System.out.println("颜色;"+nbc.getColor()+" "+"cpu:"+nbc.getCpu()); NoteBookComputer nbc2=new NoteBookComputer(); nbc2.setColor('红'); nbc2.setCpu(1060); System.out.println("颜色;"+nbc2.getColor()+" "+"cpu:"+nbc2.getCpu()); } } public class NoteBookComputer { private char color; private int cpu; public NoteBookComputer() { } public NoteBookComputer(char color, int cpu) { this.color = color; this.cpu = cpu; } public char getColor() { return color; } public void setColor(char color) { this.color = color; } public int getCpu() { return cpu; } public void setCpu(int cpu) { this.cpu = cpu; } }
6、定义两个类,描述如下: [必做题]
• 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。
class text4{ public static void main(String[] args) { person p=new person("zhangsan",1.73,33); p.sayHello(); person p2=new person("lisi",1.74,44); p2.sayHello(); } } public class person { private String Name; private double Tall; private int Age; public void sayHello(){ System.out.println("你好我们名字叫"+Name); } public person() { } public person(String name, double tall, int age) { Name = name; Tall = tall; Age = age; } public String getName() { return Name; } public void setName(String name) { Name = name; } public Double getTall() { return Tall; } public void setTall(Double tall) { Tall = tall; } public int getWeight() { return Age; } public void setWeight(int weight) { this.Age = weight; } }