基本的C#数字运算示例，执行两个数的加法、减法运算，返回相加、相减后的结果，实例化类对象，定义一个死循环，以便循环输入数据，记录运算符号，以运算符号为条件进行判断，判断是否为加号，判断是否为减号，不符合上面所有情况，实现基本的加法、减法运算。-Basic C# number crunching example, the addition of two numbers, subtraction, return the sum, the result of the subtraction, the instantiated class object, define a cycle of death, for recycling the input data record Operators Operators conditions to judge, to determine whether the plus sign to determine whether the minus sign, does not meet all of the above, the basic addition, subtraction.