abstract class

[Basu Patel]

Is this true or false?
All abstract classes have implicitly abstract methods? meanning I cannot have concrete methods in an abstract class?
Marcus Green Exam 3 states it to be true
but Patric Naughton states that concrete methods are allowed in an abstract class, which mean these methods have a method body and cannot be abstract.
Please help me clarify this doubt!
Thanx

[Sunita Vontel]

Yes abstract classes can have non abstract methods i.e methods with the body.

[Basu Patel]

Please justify how can these non-abstract methods in an abstract
class be implicitly abstract?
Thanx

[Sunita Vontel]

Hi Basu
They are not implicitly abstract.Only those methods are abstract which u declare them as abstract and only they need to be implemented.
check this
abstract class ab
{
abstract void sun();
void nonabs()
{
System.out.println("nonabs");
}
}
class abs extends ab
{
void sun()
{
System.out.println("in sun");
}
}
The method nonabs is not abstract.

[mmkris_1]

hi everyone
I think a class needs to declared abstract if it has one or more abstract methods. The viceversa need not be true i.e. if a class is abstract then it should contain only abstract methods.

[Basu Patel]

From what I understand , Marcus Green exam 3, has made this mistake of calling all methods in an abstract class as implicitly
abstract.
Thank You guys for time.
Basu