Liscov substitution principle
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The document discusses the Liskov Substitution Principle, a key concept within the SOLID principles of object-oriented design defined by Barbara Liskov in 1987. It states that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program. Additionally, it emphasizes that inheriting classes must maintain expected behavior when instances are substituted.
Liscov substitution principle
- 2. S: Single Responsibility Principle O: Open/Closed for Principle L: Liskov Substitution Principle I: Interface Segregation Principle D: Dependency Inversion Principle SOLID Principles 2 OOD principles Not design Patterns By Bob Martin and Michel Features
- 3. The principle, that Barbara Liskov defined in 1987 in her conference keynote named "Data abstraction and hierarchy". Liscov Substitution Principle 3
- 4. Liskov Substitution Principle 4 Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
- 5. Liskov Substitution Principle 5 You should be able to replace any instances of a parent class with an instance of one of its children without creating any unexpected or incorrect behaviors.
- 6. Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program. You should be able to replace any instances of a parent class with an instance of one of its children without creating any unexpected or incorrect behaviors. Liskov Substitution Principle 6 If S is a subtype of T, then objects of type T may be replaced with objects of type S
- 7. 7 If class Man is inherited from class Human, then objects of class Human may be replaced with objects of class Man.
- 8. 8 If class ……….. is inherited from class ……………., then objects of class ……... may be replaced with objects of class ………....
- 9. 9 …………...without altering the correctness of that program.
- 10. Code Example 10
- 11. 11 If class AdminUser is inherited from class User, then objects of class User may be replaced with objects of class AdminUser
- 12. Thank You 12