Without too much programming experience, the system maintenance of the interactive system for more than half a year, learn the code of others, accept the user's "metamorphosis", change the system to meet the needs of users, and experience the unreasonable system of the old system
It is really necessary (but maintenance system is best for companies that are not too important, and can get tossing systems)
Otherwise, the code written at the beginning is often unopeless. You can't experience the experienced programmer why should we carefully design the system
