negative or operation的意思|示意

Unary operators perform an operation on a single operand, such as returning the negative or positive value of a numeric expression.

一元运算符对单个操作数执行操作，如返回数值表达式的负值或正值。

In recent years "managed the city" the operation pattern to obtain the certain result while our country, also appeared some deviations or the negative effect.

近年来“经营城市”运作模式在我国取得一定成效的同时，也出现了一些偏差或负面效应。

res is the usual result of an I/O operation: the number of bytes transfered, or a negative error code.

res是IO操作的通常结果：传输的字节数，或者负值的错误码。