C++ Polymorphism

What is Polymorphism?

Polymorphism means "many forms".

It allows functions to behave differently depending on context.

Types of Polymorphism

• Compile-Time (Function Overloading)
• Runtime (Virtual Functions)

Compile-Time Polymorphism

Achieved using function overloading.

Runtime Polymorphism (Without virtual)

Without virtual, the base class function is called even if the object is derived.

Runtime Polymorphism (With virtual)

Using virtual ensures the correct function is called at runtime.

Override Keyword

The override keyword ensures correct overriding.

Full Example

Why Polymorphism is Important

• Flexible code
• Reusable design
• One interface, many implementations

Common Mistakes

• Forgetting virtual keyword
• Confusing overloading vs overriding
• Using base pointers incorrectly

Practice

Create a base class Shape and derived classes Circle and Square. Use virtual functions.

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