很简单的计算器功能的小型java程序源代码，只能两个数的加减乘除，自己可以扩展，这里重点是教给初学者编程的思想，比如即使是简单的函数，也要先定义再调用，这样模块化思想很清晰，定义数字的时候如果考虑扩展的问题，最好定义数组等等。-Very simple calculator function small java program source code, only two-digit addition and subtraction, multiplication and division, their own can be extended here just to beginners focusing on programming ideas, such as even simple functions, it must first define and then call so modular thinking very clearly defined numbers when considering extended defined array.