In an abstract class, there is no fixed required number of abstract methods: it can have

  • zero abstract methods
  • one abstract method
  • or many abstract methods

Key idea

In languages like Java:

  • If a class has at least one abstract method, the class must be declared abstract.
  • However, an abstract class is allowed to have 0 abstract methods ; it might be marked abstract simply to prevent direct instantiation or to act as a common base type.

So the answer to “how many abstract methods are there in an abstract class?” is:

An abstract class can contain any number of abstract methods, including none at all.