Override
Overriding is defining a more specific implementation that replaces inherited behavior for a type or object while preserving the operation’s interface.
Kotlin in Action, 2E
Method overriding is the definition of a subclass member function that replaces an inherited implementation with the same signature.
- How it is used
- Marks intentional replacements of inherited functions and properties while implementing interfaces or specializing subclasses.
- How deep it goes
- Explains open and final eligibility, runtime dispatch, interface conflicts, property implementations, and extension-function limits.
- Examples
- Uses View and Button clicks, competing Clickable and Focusable defaults, user nickname properties, Customer equality, and Point equality.
- What you can do after
- Apply it to implement interface contracts, specialize explicitly open members, resolve default-method conflicts, and customize object behavior.
Software Design for Python Programmers
Method overriding is the definition of a subclass method with the same operation interface as an inherited superclass method, causing the subclass implementation to be selected for subclass instances.
- How it is used
- Uses overriding to give subclass instances related behavior while preserving a common superclass interface.
- How deep it goes
- Explains signatures, runtime dispatch, super(), type-hint hazards, and contract concerns without descending into language-runtime internals.
- Examples
- Demonstrates Item and OrganicItem pricing, then exposes an incompatible operate() override through a TypeError.
- What you can do after
- Apply it via Python subclass methods, reuse superclass behavior with super(), and diagnose incompatible overrides using runtime failures and type checking.
Read how Software Design for Python Programmers explains override →
Python How-To
Method overriding is the object-oriented technique in which a subclass defines a method with the same name as an inherited method to provide a specialized implementation.
- How it is used
- Customizes inherited behavior for specialized subclasses and produces meaningful string representations for class instances.
- How deep it goes
- Defines complete and partial overrides, demonstrates __str__, and traces single-superclass lookup through method resolution order.
- Examples
- Uses Task.__str__, Supervisor.login, Supervisor.logout, super(), and Class.mro() as concrete demonstrations.
- What you can do after
- Apply overriding to replace or extend inherited methods and customize printed representations in Python classes.
Related concepts
- inheritanceuses · Inheritance is a mechanism by which a child type or element receives properties, values, or behavior from a parent, subject to system rules and possible overrides.
- C++produced by · C++ is a statically typed, general-purpose programming language supporting procedural, object-oriented, generic, and low-level systems programming.
- pass-through changeimplemented by · Pass-through change is wrapping an existing method so that calls are forwarded to the original implementation while additional behavior is applied around it.
- open modifierconfigured by · The open modifier is a Kotlin declaration modifier that permits a class to be subclassed or a member to be overridden.
- polymorphismuses · Polymorphism is a programming-language capability that lets a common interface or operation work with values of different types while allowing behavior to vary by type or implementation.
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