How can the Object class be a super class of subclasses?

Question

Fact 1:

Java does not support multiple inheritance.

Fact 2:

Object is a superclass of all other classes

If I have a class Parent and a class Child which is inheriting the class Parent:

class Parent {

}

class Child extends Parent {

}

In this case, how will the class Child inherit the Object class, if Java does not support multiple inheritance?

How is the relationship between these three defined?

Option 1:

Option 2:

Answer 1

Object might not be a direct parent, but it's always a super parent.

Child extends Parent
Parent extends Object

 |
 V

Child [indirectly] extends Object

Answer 2

The JavaDoc says:

Class Object is the root of the class hierarchy. ...

If a class does not extend any other class by decalring it using the keyword extends it extends though implicit from Object.

The documentation says:

In the absence of any other explicit superclass, every class is implicitly a subclass of Object.

See the Example 8.1.4-1 "Direct Superclasses and Subclasses" in JLS, chapter 8.1.4

It shows that a class Point { int x, y; } "is a direct subclass of Object"

Moreover the documentation says:

Classes can be derived from classes that are derived from classes that are derived from classes, and so on, and ultimately derived from the topmost class, Object. Such a class is said to be descended from all the classes in the inheritance chain stretching back to Object.

The JLS states it short and formal:

The subclass relationship is the transitive closure of the direct subclass relationship.

Thus class Object is the superclass of all classes.

But the documentation also says:

Excepting Object, which has no superclass, every class has one and only one direct superclass (single inheritance).

Going on with the example a class ColoredPoint extends Point { int color; } "is a direct subclass of class Point.". By the transitive relationship it's a (non-direct) subclass of class Object.

Summarizing:
Object is either the direct superclass or by transitive relationship the last superclass of any other class.

Answering the questions:

• Java does not support multiple inheritance: It provides single inheritence in a transitive way. Every class extends directly only one supercalss.
• How is the relationship: The class Parent corresponds to the class Point and the class Child to the class ColoredPoint of the JLS example. Only Option 2 shows this relation.