Java第三次实验（类）

方法1：主类中第一行代码是

Cylinder cylinder=new Cylinder();

package work02;

class Cylinder{
	double r;  //r为圆柱的底面半径
	double h;  //h为圆柱的高	
	void area(){
		double area;
		area = 2*Math.PI*r*r+2*Math.PI*r*h;
		System.out.println("圆柱的面积为："+area);		
	}
	void volume(){
		double volume;
		volume = Math.PI*r*r*h;
		System.out.println("圆柱的体积为："+volume);
	}
	
}
public class Leitest {
	public static void main(String args[]){
		Cylinder yuanzhu = new Cylinder();
		yuanzhu.r = 1;
		yuanzhu.h = 2;
		yuanzhu.area();
		yuanzhu.volume();
	}
}

方法2：主类中第一行代码是

Cylinder cylinder=new Cylinder(a,b); //a是输入的参数半径radius，b是输入的高height.

package work02;

class Cylinder02{
	double r;double h;
	Cylinder02(double a, double b){
		r = a;h =b;	
	}
	void area(){
		double area;
		area =2*Math.PI*r*r+2*Math.PI*r*h;
		System.out.println("圆柱的面积为："+area);
	}
	void volume(){
		double volume;
		volume = Math.PI*r*r*h;
		System.out.println("圆柱的体积为："+volume);
	}
}

public class Leitest02 {
	public static void main(String args[]){
		Cylinder02 yuanzhu = new Cylinder02(1,2);
		yuanzhu.area();
		yuanzhu.volume();
	}

}

总结比较有用的地方

实现代码：

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作者|daiguoxi
时间|2021/3/17
邮箱|daiguoxi@gmail.com
公众号|DGX杂学