Object-oriented programming (OOP) organizes software around objects that combine data with the code that changes it. These tutorials teach each OOP concept with the same examples in C++, Java and Python, so you can see what is common to all three languages and where they differ. Every program is compiled and run with GCC, Clang, Java 21 and Python 3, and the code is in the MYCPLUS examples repository on GitHub.
Start here: Object-Oriented Programming: Concepts, Pillars and Techniques explains all six concepts with one example, compares OOP with procedural code, and introduces SOLID and design patterns.
override.friend, resource-owning classes and the cost of private.
How one call runs different code for different objects: overloading, overriding, virtual functions, generics and duck typing in C++, Java and Python.
How OOP differs from procedural code, what its four pillars mean, and the techniques that keep object-oriented code easy to change, in three languages.
Why q = p1 copies an object in C++ but shares it in Java and Python, how equality differs from identity, and how each language ends an object’s life.
How abstract classes, interfaces and Python protocols separate what code does from how, with a testable clock example in C++, Java and Python.
One base class and two subclasses written in C++, Java and Python, the five types of inheritance, and why a subclass counted six tags when three were added.
How private state and checking methods keep an object valid, why a getter can leak it, and how Python gets encapsulation from properties and convention.
One Temperature class written in C++, Java and Python, what a class stores once versus per object, and why a Python list in a class body was shared.