Abstract Class and Inheritance

[Hiep Nguyen]

i write an abstract class that extends JFrame, and a subclass is extended the abstract class. but when i compile, it make an error at contructor. what should i do?
this is my code
*******************

class abstract ListForm extends JFrame{
  public ListForm(String title){
     super(title);
  }
  //some abstract motheds
}
class MyList extends ListForm{
   public MyList(String title){
     super(title);
   }
   //implements these abstract methods here
}
[error]
and when compile, MyList class has the error massage like this :
MyList.java [18:1] cannot resolve symbol
symbol  : constructor MyList  ()
location: class ListForm
public class MyList extends ListForm {
[/error]

thank you

[Thomas Paul]

The normal reason for getting this error is, since the abstract class doesn't have a default constructor all the constructors of the extending class must have "super(title);" as the first staement in their constructors. The code snip you showed us should be fine.

[Michael Morris]

Hi Hiep,
You have a syntax error on your first ListForm class declaration: it should be abstract class instead of class abstract but that should not cause the error you say the compiler is indicating. By changing that, your code should compile. There must be some problem in the implementation of the abstract methods.
Hope this helps,
Michael Morris

[Hiep Nguyen]

thanh you for your replies !
in my working code, i passed wrong parameters, the misstake takes me long time to debug so i 'm really supid man