Actual mechanism of object class as the superclass for all classes

Hi all

We know that all the classes of the java platform are the descendants of the object class. Even if we write a new class, in the absence of any explicit superclass, each class is implicitly a subclass of the object. As we expand it, not directly the object class, then how is the methods of the object are inherited from the class Sub that we wrote? How the java to maintain this hierarchy?

Can you please explain this carefully?

Thanks in advance,
Uday

Udaya Shankara Gandhi wrote:
Hi all

We know that all the classes of the java platform are the descendants of the object class. Even if we write a new class, in the absence of any explicit superclass, each class is implicitly a subclass of the object. As we expand it, not directly the object class, then how is the methods of the object are inherited from the class Sub that we wrote? How the java to maintain this hierarchy?

Because the language is defined in this way. Compilers implement the language according to the rules of the DG JLS. Exactly how they do it is not defined. It is each compiler. As long as it respects the rules defined in the JLS to the code analysis and generate the .class file, that's all that matters. However, somewhere in the compiler's code which is about:

if (class has an extends clause) {
  generate corresponding bytes for extends in .class file
}
else {
  generate bytes for extends java.lang.Object in .class file
}

No great mystery, or philosophical question.

Tags: Java

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