The Liskov Substitution Principle is a fundamental concept in object-oriented programming, ensuring that derived classes can be used in place of their base classes without altering the correctness of the program.

遇事要再三考虑，慎重行事，第一重要的是不要自欺欺人。

释义：如果田地没成熟就收获，还不如不种；如果养育的孩子不学好，还不如没有。