Liskov substitution principle
OBJECT-ORIENTED PROGRAMMING PRINCIPLE STATING THAT, IN A COMPUTER PROGRAM, IF S IS A SUBTYPE OF T, THEN OBJECTS OF TYPE T MAY BE REPLACED WITH OBJECTS OF TYPE S WITHOUT ALTERING ANY OF THE DESIRABLE PROPERTIES OF THE PROGRAM (CORRECTNESS, ETC.)
Liskov Substitution Principle; Substitutability; Liskov substitution
The Liskov substitution principle (LSP) is a particular definition of a subtyping relation, called strong behavioral subtyping, that was initially introduced by Barbara Liskov in a 1988 conference keynote address titled Data abstraction and hierarchy. It is based on the concept of "substitutability" a principle in object-oriented programming stating that an object (such as a class) and a sub-object (such as a class that extends the first class) must be interchangeable without breaking the program.