说明：  Rhino支持javascript标准的所有特性，如赋值、运算、判断语句、循环语句、甚至简单的io操作。Rhino很简单易用，我以一个例子来说明，这个例子就是允许用户设定一个使用x,y两个变量进行一定逻辑算术运算（运算规则用户用javascript定义），并允许用户对x,y赋值，然后运行得出计算结果
(Rhino support all standard features, such as assignment, calculation and judgment statement, the loop is, or even simple io operations. Rhino is very simple to use, I have an example to illustrate that this example is to allow users to use one set x, y two variables must logical arithmetic operations (Operational Rules uses javascript definition), and allows users to x, y assignment, and then come running results)