You can see that the implementation of the add () method on the CalculatorService no longer obtains the calcID identifying the calculator state as an input parameter. 您可以看到,CalculatorService中的add()方法的实现不再获得calcID来确定作为输入参数的计算器状态。
This program has no programming capability built in and is intended to be used as a simple symbolic math calculator. 此程序没有内置的编程功能,旨在用作简单的符号数学计算器。