package 面向对象编程;public class juxing {    double chang;    double kuan;    juxing(double chang,double kuan)    {        this.chang=chang;        this.kuan=kuan;    }    //计算面积    double getMianJi()    {        return this.chang*this.kuan;    }    public static void main(String[]args)    {        juxing myJX=new juxing(1,5);        System.out.println("矩形的面积="+myJX.getMianJi());        }}