java第九周随堂
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]
package demo9_1ninthweek_Thursday;
public class point_func {
int x;
int y;
public point_func() {
}
public point_func(int x0, int y0) {
this.x = x0;
this.y = y0;
}
public void movePoint(int dx, int dy) {
this.x += dx;
this.y += dy;
}
}
package demo9_1ninthweek_Thursday;
public class point_test {
public static void main(String[] args) {
// TODO Auto-generated method stub
point_func p1 = new point_func(2, 2);
p1.movePoint(6, 7);
System.out.println("p1当前的坐标为：" + p1.x + "," + p1.y);
point_func p2 = new point_func();
p2.movePoint(6, 7);
System.out.println("p2当前的坐标为：" + p2.x + "," + p2.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
package demo9_1ninthweek_Thursday;
public class Rectangle_func {
private int length;
private int width;
Rectangle_func(int length, int width) {
this.length = length;
this.width = width;
}
public void showAll() {
System.out.println("矩形长为:" + length + "\t" + "矩形的宽为:" + width);
System.out.println("矩形的面积为:" + getArea() + "\t" + "矩形的周长为:" + getPer());
}
public int getPer() {
return 2 * (length + width);
}
public int getArea() {
return length * width;
}
}
package demo9_1ninthweek_Thursday;
public class Rectangle_test {
public static void main(String[] args) {
// TODO Auto-generated method stub
Rectangle_func r = new Rectangle_func(4, 6);
r.showAll();
}
}
• 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。
package demo9_1ninthweek_Thursday;
public class computer_func {
char color;
int model;
computer_func() {
}
computer_func(char color, int model) {
this.color = color;
this.model = model;
}
void a() {
System.out.println("笔记本的颜色为：" + color + " 型号为：" + model);
}
public static void main(String[] args) {
computer_func a = new computer_func('a', 1999);
a.a();
}
}
4、定义两个类，描述如下： [必做题]
• 4.1定义一个人类Person：
• 4.1.1定义一个方法sayHello()，可以向对方发出问候语“hello,my name is XXX”
• 4.1.2有三个属性：名字、身高、年龄
• 4.1.3通过构造方法，分别给三个属性赋值
• 4.2定义一个Constructor类：
• 4.2.1创建两个对象，分别是zhangsan，33岁，1.73；lishi，44，1.74
• 4.2.2分别调用对象的sayHello()方法。
package demo9_1ninthweek_Thursday;
public class Person {
String name;
int age;
double height;
public void sayHello() {
System.out.println("hello,my name is " + this.name);
}
public void getValue(String name, int age, double height) {
this.name = name;
this.age = age;
this.height = height;
}
}
package demo9_1ninthweek_Thursday;
public class person_test {
public static void main(String[] args) {
// TODO Auto-generated method stub
Person p1 = new Person();
p1.getValue("zhangsan", 33, 1.74);
p1.sayHello();
Person p2 = new Person();
p2.getValue("lishi", 44, 1.74);
p2.sayHello();
}
}
