Abstract class in Java 5 or previous

Question

I've read in a book ( Programmez en Java 5 et 6 by Claude Delannoy, in French) that in Java 5 and its previous versions, if you have an abstract method in a class then this class is abstract and it's not necessary to mention the keyword abstract before the class.

Is this statement true? I tried to find the Java SE 5 specification but it's unreachable.

Answer 1

If you want to make a class abstract,you need to declare it abstract no matter which version of java you are using.

If a class contains an abstract method,then that class also becomes abstract and you need to declare that class abstract to resolve compile issue.