An operator is a code element that performs an operation on one or more code elements that hold values 运算符是一种代码元素，可在一个或多个容纳值的代码元素上执行运算。
A common use for expressions is to perform arithmetic on variables : addition , subtraction , multiplication , or division 表达式常用于对变量执行运算：加法、减法、乘法或除法。
Compound assignment statements first perform an operation on an expression before assigning it to a programming element 复合赋值语句先对表达式执行运算，然后才将表达式赋给编程元素。
It widens each operand as necessary to the appropriate data type before the operation , and the result has that data type 类型执行运算。它在运算前根据需要将每个操作数扩展为相应的数据类型，运算结果也为该数据类型。
The nullability property of arithmetic operators over the floating point data type is changed to nonnullable for the case where the inputs are nonnullable and ansi warnings is on 在输入不可为空并且ansi _ warnings为on的情况下，对浮点数据类型执行运算的算术运算符的为空性属性将更改为不可为空值。
While floating - point data is stored in the fprs in double - precision format , a set of single - precision arithmetic instructions perform the arithmetic operation and round the final result to single - precision while detecting exceptions such as exponent overflow , underflow , and inexact that should occur with a single - precision operation 虽然浮点数以双精度格式存储于fpr中，但是，有一组单精度运算指令，可以执行运算操作并将最终结果舍入为单精度，同时检测进行单精度操作时可能会发生的异常（比如指数溢出、下溢和失去精度） 。
