这样写即可: public class b20306 { static abstract class area //add static { public int k1; public int k2; abstract public int get_area(); }
static class area_as extends area //add static { public area_as(int v1,int v2) { k1=v1; k2=v2; } public int get_area() { return k1*k2; } } public static void main(String agrs[]) { area_as v1 = new area_as(20,30);//这行有错误!!到底怎么回事??? int a=v1.get_area(); System.out.println(a); }}
public class b20306
{
static abstract class area //add static
{
public int k1;
public int k2;
abstract public int get_area();
}
static class area_as extends area //add static
{
public area_as(int v1,int v2)
{
k1=v1;
k2=v2;
}
public int get_area()
{
return k1*k2;
}
}
public static void main(String agrs[])
{
area_as v1 = new area_as(20,30);//这行有错误!!到底怎么回事??? int a=v1.get_area();
System.out.println(a);
}}