“Java”编程中如何求矩形的面积？

代码如下：

import java.util.*

public class Rectangle {

private float length//定义长变量

private float width// 宽变量

public Rectangle(float length,float width){

this.length=length

this.width=width

}

public float getGirth(){

return (length+width)*2

} //求周长方法

public float getArea(){

return length*width

} //求面积方法

public static void main (String[] args) {

Scanner in=new Scanner(System.in)//调用输入方法

System.out.println ("请输入矩形的长：")

float a=in.nextFloat()

System.out.println ("请输入矩形的宽：")

float b=in.nextFloat()

System.out.println ("矩形周长为："衡做+new Rectangle(a,b).getGirth())

System.out.println ("矩形面积兄拦升为："+new Rectangle(a,b).getArea())

}

}

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class Rectangle{

private int width = 2

private int length = 1

public int getWidth(){

return this.width

}

public void setWidth(int w){

this.width = w

}

public int getLength(){

return this.length

}

public void setLength(int l){

this.length = l

}

public int getArea(){

return this.length * this.width

}

public int getCircumference(){

return (this.length + this.width) * 2

}

public Rectangle(){}

public Rectangle(int l, int w){

this.length = l

this.width = w

}

}

public class demo{

public static void main(String[] args) {

Rectangle rect = new Rectangle(30, 8)

System.out.print("长方形前咐的面积是：")

System.out.println(rect.getArea())

System.out.printf("配拿长方培悔搭形的周长是：%d\n", rect.getCircumference())

}

}

// 矩形

public class RectangleDemo {

public static void main(String[] args) {

RectangleDemo demo = new RectangleDemo(12, 32)

System.out.println(demo.getPerimeter())

System.out.println(demo.getArea())

demo = new RectangleDemo()

System.out.println(demo.getArea())

System.out.println(demo.getPerimeter())

demo.setHeight(50)

demo.setWidth(30)

System.out.println(demo.getArea())

System.out.println(demo.getPerimeter())

}

// 求周

public double getPerimeter() {

return (height + width) * 2

}

// 求面积

public double getArea() {

return height * width

}

public RectangleDemo(double height, double width) {

this.height = height

this.width = width

}

public RectangleDemo() {

this.height = 10

this.width = 10

}

private double height// 高纯盯度

private double width// 宽度

public double getHeight() {

return height

}

public void setHeight(double height) {

this.height = height

}

public double getWidth() {

return width

}

public void setWidth(double width) {

this.width = width

}

}

编写矩做拦和形类RectangleJava程序矩形类两数据员别rLength宽rWidth通getLength()、getWidth()、getArea()别查看矩形、宽面积通setLength()setWidth()重新设置矩形宽衡丛

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