public class Name {
            
    public static void main(String[] args) {
              Yuan yuan1=new Yuan();
        System.out.println("半径为"+yuan1.Banjing +"的圆的面积是："+yuan1.Mianji());
        }
}
         class Yuan{
             double Banjing;
            void banjing(){
                 Banjing=4.5;
             }
            void banjing(double newBanjing){
                Banjing=newBanjing;
            }
             double Mianji(){
                return Banjing*Banjing*Math.PI;
         }
}
执行结果显示如下：

你的这个程序在 yuan1.Banjing()的地方提示有错误啊，是怎么回事？