设计一个名为 Car 的类,具体要求如下: (1) int 类型的成员变量 speed 表示汽车的速度(默认为0);Boolean 型的成员变量on表示汽车是否启动(默认为 false) ;double类型的成员变量 weight 表示汽车重量(t,默认为1.2);String 类型的成员变量 color表示汽车的颜色(默认为 blue)。 (2) 用无参构造方法创建默认汽车。 (3) 编写设置和存取这些数据域的方法。 (4) 用toString 方法返回描述汽车的字符串,如果汽车起动,该方法返回汽车的速度、颜色和重量。如果汽车不在启动状态,该方法返回字符串“car is off” ,以及汽车的颜色和重量等信息。 (5) 编写一个测法程序,创建两个Car对象,第一个对象设置为 120km/h、1.5t、black、启动,第二个对象设置为0km/h、1.2t、red、关闭。通过调用tostring()方法显示两个对象的信息
时间: 2023-04-06 17:00:36 浏览: 428
Car 类的代码如下:
```
public class Car {
private int speed;
private boolean on;
private double weight;
private String color;
public Car() {
speed = 0;
on = false;
weight = 1.2;
color = "blue";
}
public void setSpeed(int speed) {
this.speed = speed;
}
public int getSpeed() {
return speed;
}
public void setOn(boolean on) {
this.on = on;
}
public boolean isOn() {
return on;
}
public void setWeight(double weight) {
this.weight = weight;
}
public double getWeight() {
return weight;
}
public void setColor(String color) {
this.color = color;
}
public String getColor() {
return color;
}
public String toString() {
if (on) {
return "speed: " + speed + "km/h, color: " + color + ", weight: " + weight + "t";
} else {
return "car is off, color: " + color + ", weight: " + weight + "t";
}
}
}
```
测试程序的代码如下:
```
public class TestCar {
public static void main(String[] args) {
Car car1 = new Car();
car1.setSpeed(120);
car1.setWeight(1.5);
car1.setColor("black");
car1.setOn(true);
Car car2 = new Car();
car2.setWeight(1.2);
car2.setColor("red");
System.out.println(car1.toString());
System.out.println(car2.toString());
}
}
```
运行结果如下:
```
speed: 120km/h, color: black, weight: 1.5t
car is off, color: red, weight: 1.2t
```