1.17作业

package lianxi;
public class lei {
    double Chang;
                
                double Kuan;
                
void M(double x1,double x2)
                {
                    Chang = x1;
                    Kuan=x2;
                    double MianJi=Chang*Kuan;
                    //double s=Chang*Kuan;
                    System.out.println("矩形的面积="+MianJi);
                }
                lei(){
                    
                }
            
                lei(double y1,double y2){
                    Chang=y1;
                    Kuan=y2;
                    double mianji=Chang*Kuan;
                }
                    
                double L(double t1,double t2){
                    return(t1*t2);
                }
                
                void LL(){
                    
                    double mianji=Chang*Kuan;
                    System.out.println("长方形的面积是"+mianji);
                }
                boolean lm(){
                boolean n=true;
                if (Chang==0||Kuan==0){
                    n=false;
                    System.out.println("这不是四边形");
                }else{
                    System.out.println("四边形的面积是"+Chang*Kuan);
                }return n;
            }
}

package lianxi;
public class shiyonglei {

    public static void main(String[] args) {
         //无返回有参数
            lei S=new lei();
          S.M(23,23);
           System.out.println("长方形的面积是"+S.Chang*S.Kuan);
           
           //构造方法
           lei Z=new lei(2,4);
           System.out.println("矩形的面积是"+Z.Chang*Z.Kuan);
            
           //有返回有参数
           lei mm=new lei();
           System.out.println("长方形的面积是"+mm.L(5, 8));
           
           //无返回无参数
           lei ll=new lei();
         ll.Chang=23;
         ll.Kuan=2;
         ll.LL();
        
           //有返回无参数
         lei LM=new lei();
         LM.Chang=3;
         LM.Kuan=4;
         System.out.println(LM.lm());
         
    }

}