Why Java Does Not Support Multiple Inheritance?

Ramesh Fadatare

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Mar 21, 2025

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If you’re preparing for Java interviews or brushing up your OOP knowledge, you’ve probably come across this classic question:

Why does Java not support multiple inheritance with classes?

Let’s break this down in a simple and clear way — with examples, problems, and solutions — so you’ll never forget the answer again.

✅ Short Interview Answer

Java does not support multiple inheritance with classes to avoid ambiguity and complexity caused by the Diamond Problem. Instead, Java supports multiple inheritance using interfaces.

🧠 What is Multiple Inheritance?

In object-oriented programming, multiple inheritance means a class can inherit from more than one class.

Example in C++ (which allows multiple inheritance):

class A {
public:
    void show() { cout << "Class A"; }
};

class B {
public:
    void show() { cout << "Class B"; }
};

class C : public A, public B {
    // Ambiguity arises here
};

If you call show() from class C, the compiler won’t know whether to use A’s or B’s method. That’s the Diamond Problem.

💥 The Diamond Problem Explained

Imagine this structure:

       A
      / \
     B   C
      \ /
       D

• B and C both inherit from A