我的第一个JAVA程序——计算正方形面积

package all;
 class square{
   private double side;//side边长
   public void setside(double a)
    {	 side=a;
    }
   public double getside()//返回边长
    {	 return side;
    }
   public double area()//返回面积
   {	 return side*side;
   }	
}
 public class square1{	  
public static void main(String[] args) {
	out1 x,y;
	x=new out1();
	y=new out1();
	x.setside(2);
	y.setside(4);
         System.out.println("x.side="+x.getside());
	System.out.println("y.side="+y.getside());
	System.out.println("x.area="+x.area());
	System.out.println("y.area="+y.area());
	}
}