Which is true about an anonymous inner class?

In simple words, a nameless inner class is called anonymous inner class. Java anonymous inner classes are useful when we need only one object of the class. Since an anonymous inner class does not have a name, it cannot have a constructor because we know that a constructor name is the same as the class name.

In Java, a class can contain another class known as nested class. It’s possible to create a nested class without giving any name. A nested class that doesn’t have any name is known as an anonymous class. An anonymous class must be defined inside another class. Hence, it is also known as an anonymous inner class.

It can extend exactly one class and implement exactly one interface . It can implement multiple interfaces regardless of whether it also extends a class. It can extend exactly one class or implement exactly one interface.