In order to make the developed program have better readability,maintainability and robustness,thus making the program structure more reasonable and more efficient,there is a need for rules in coding.

• 为了使开发出来的程序具有更高的可读性、可维护性和稳健性,使程序的结构更加合理,提高程序的开发与执行效率,必须约束程序的编写;