1. Abstract class
2. Abstract functions
3. Abstract keywords
The keyword abstract indicate that a method must always be redefined in a subclass. It means that overriding is compulsory.
But there are some conditions for abstract class
You can not instantiate objects directly.
Abstract methods of an abstract class must be defined in its subclass.
You can not declare abstract constructors or abstract static methods.
#java
#abstract
#class
