Inner classes

[majohnad majohnad]

Is the below statements are true?
"An abstact class must declare at least one abstract method"
"A local class can be declared abstract."

[Rattan Mann]

You are right on both counts. In fact, local inner class can be declared only abstract or final. It can't be declared coderanch, protected, private etc.
Rattan

[Corey McGlone]

"An abstact class must declare at least one abstract method"

False.
If the class contains 1 or more abstract methods, it must be declared abstract, but it is not required that a class contain an abstract method to be declared abstract.

"A local class can be declared abstract."

True.
An Inner Class isn't really that different from a top-level class - they can be abstract.
I hope that helps,
Corey

[Francis Siu]

hi majohnad
"An abstract class must declare at least one abstract method"
I make sure that the above statement is false
because abstract class can contains no abstract method.For example MouseAdapter or KeyAdapter.

[Roger Chung-Wee]

An abstract class does not have to have any abstract methods, or any methods at all, but must be declared abstract if it has any abstract methods.
A method-local class (which is not an anonymous class) can be abstract. It can also be final or strictfp. No other modifiers are allowed, because such a class cannot be accessed from the outside, so the other modifiers make no sense.

class TestLocal
{
    void f()
    {
        abstract class A {} //legal
        final class B {} //legal
        strictfp class C {} //legal
        abstract strictfp class D {} //legal
        final strictfp class E {} //legal
        public class F {} //illegal
        protected class G {} //illegal
        private class H {} //illegal
        static class I {} //illegal
    }
}

[ April 21, 2003: Message edited by: Roger Chung-Wee ]