java小程序 那位帮忙看看 不知道错在那里
class Shape
{
void draw(){}
void erase(){}
}
class Circle extends Shape
{
void draw()
{
System.out.println("Circle.draw()");
}
void erase()
{
System.out.printltn("Circle.erase()");
}
}
class Square extends Shape
{
void draw()
{
System.out.println("Square.draw()");
}
void erase()
{
System.out.println("Square.erase()");
}
}
class Triangle extends Shape
{
void draw()
{
System.out.println("Triangle.draw()");
}
void erase()
{
System.out.println("Triangle.erase()");
}
}
public class BindingTester
{
int n;
public static void main(String[] args)
{
Shape[]s=new Shape[9];
}
for(int i=0;i<s.length;i++)
{
n=(int)(Math.random()*3);
switch(n)
{
case 0 : s[i]=new Circle; break;
case 1 : s[i]=new Square(); break;
case 2 : s[i]=new Triangle();
}
}
for(int i=0;i<s.length;i++)s[i].draw();
}