作业题

package juxing;

public class juxing {
    
    



    void juxing()
    {
        chang=1;
        kuan=2;
    }
    
    double chang;
    double kuan;
    
    void mianji()
    {
        System.out.println("矩形面积="+chang*kuan);
    }
    
    
}






package juxing;

public class ceshi {
    
    public static void main(String[] args) {
        
        juxing myju=new juxing();
         myju.chang=2;
        myju.kuan=3;
        myju.mianji();
    }
}