Question

java编程:定义一个圆类,属性为半径,方法为对输入的半径计算其周长和面积,

并输出半径、周长和面积，要求定义构造方法用来初始化半径

Answer 1

public class Test {
	private double r;
	public double getR() {
		return r;
	}
	public void setR(double r) {
		this.r = r;
	}
	public Test(double r) {
		super();
		this.r = r;
	}
	public void MJ(){
		System.out.println("圆的面积为：" + (3.14 * this.getR() * this.getR()));
	}
	public void ZC(){
		System.out.println("圆的周长为：" + (2 * 3.14 * this.getR()));
	}
	public static void main(String[] args) {
		Test t1 = new Test(4.5);
		System.out.println("圆的半径为：" + t1.getR());
		t1.MJ();
		t1.ZC();
	}
}

Answer 2

java编程定义一个类圆属性半径方法，计算周长面积设置半径读取半径急java编程定义一个类。

java编程定义一个类圆属性半径，方法计算周长面积设置半径读取半径

class Circle 

{\x09private double r;

\x09public void setR(double r)

\x09{

\x09\x09this.r=r;

\x09}

\x09public double getArea()

\x09{

\x09\x09return Math.PI*r*r;

\x09}

\x09public double getPerimeter()

\x09{

\x09\x09return 2*Math.PI*r;

\x09}

public double getRadius()

{return r;

}\x09public static void main(String args[])

\x09{\x09

\x09\x09Circle c1=new Circle();

\x09\x09Circle c2=new Circle();

\x09\x09c1.setR(50);

\x09\x09c2.setR(80);

\x09\x09System.out.printf("c1面积为：%.3f\r\n",c1.getArea());

\x09\x09System.out.printf("c1周长为：%.3f\r\n",c1.getPerimeter());

\x09\x09System.out.printf("c2面积为：%.3f\r\n",c2.getArea());

\x09\x09System.out.printf("c2周长为：%.3f\r\n",c2.getPerimeter());\x09

\x09}

Answer 3

12345678910111213141516171819202122232425public class Test { private double r; public double getR() { return r; } public void setR(double r) { this.r = r; } public Test(double r) { super(); this.r = r; } public void MJ(){ System.out.println("圆的面积为：" + (3.14 * this.getR() * this.getR())); } public void ZC(){ System.out.println("圆的周长为：" + (2 * 3.14 * this.getR())); } public static void main(String[] args) { Test t1 = new Test(4.5); System.out.println("圆的半径为：" + t1.getR()); t1.MJ(); t1.ZC(); }}