abstraction

The Liskov Substitution Principle (LSP) defines behavioral subtyping, requiring that subtypes be completely substitutable for their base types without altering program correctness. It enforces adherence to class invariants, pre-conditions, and post-conditions within inheritance hierarchies.

To apply LSP correctly, enforce strict behavioral contracts using Abstract Data Types (ADTs) and information hiding. Ensure derived classes do not strengthen pre-conditions or weaken post-conditions and class invariants, preventing unexpected runtime errors when substituting objects.

You need data abstraction and ADTs when defining robust module interfaces that hide implementation details. This technique isolates client code from internal representation changes, ensuring correct object-oriented design and enforcing strict behavioral contracts.

Overriding methods often breaks programs due to LSP violations, where the subtype alters expected behavior by violating class invariants or weakening post-conditions. Evaluating your hierarchy against Liskov's principles ensures proper behavioral subtyping and prevents these issues.

Data abstraction defines behavior through Abstract Data Types (ADTs) and mathematical contracts, whereas simple encapsulation merely hides internal state. Data abstraction enforces strict pre-conditions and post-conditions, ensuring robust inheritance and correct behavioral subtyping.

Yes, you can validate existing interfaces using LSP checklists to verify behavioral subtyping. This process audits class invariants and contracts, ensuring your current inheritance hierarchies maintain robust substitutability and strict data abstraction.