模拟的图书馆书籍管理系统，可以实现书籍的录入和借出等一系列功能。-Simulation library books management system that can achieve entry and lending books and a series of functions.

简单的模拟图书馆的管理系统，为更复杂的编程做铺垫-Simple simulation library management system, to pave the way for more complex programming