如果方法返回void
,则没有任何可打印的内容,因此此错误消息。由于printPoint已经将数据打印到控制台,因此你应该直接调用它:
printPoint (blank);
你正在尝试打印printPoint不返回任何结果的结果。你将需要更改代码以执行以下两项操作:
class obj
{
public static void printPoint (Point p)
{
System.out.println ("(" + p.x + ", " + p.y + ")");
}
public static void main (String[]arg)
{
Point blank = new Point (3,4) ;
printPoint (blank) ;
}
}
或这个:
class obj
{
public static String printPoint (Point p)
{
return "(" + p.x + ", " + p.y + ")";
}
public static void main (String[]arg)
{
Point blank = new Point (3,4) ;
System.out.println (printPoint (blank)) ;
}
}