操作precedence（按位'和，'低于'=='） [英] Operator precedence (bitwise '&' lower than '==')

问题描述

在C编程语言，为什么按位运算符（安培;以及|）具有较低的precedence比等号（= =）？这是没有道理给我。

In the C programing language, why do the bitwise operators (& and |) have lower precedence than the equality operator (==)? It does not make sense to me.

推荐答案

您要问布赖恩Kernighan的或丹尼斯里奇。结果
从这个论坛：<一href=\"http://bytes.com/topic/c/answers/167377-operator-$p$pcedence\">http://bytes.com/topic/c/answers/167377-operator-$p$pcedence

You need to ask Brian Kernighan or Dennis Ritchie.
From this forum: http://bytes.com/topic/c/answers/167377-operator-precedence

＆将功放;＆安培;和||运营商是后来添加
      他们的短路的行为。丹尼斯里奇承认在
      回想起来，该位运算符的precedence应该有
      当加入的逻辑运算符被更改。但是，有几个
      几百KB的C源$ C ​​$ C的存在在这一点上和
      三台电脑安装基础，丹尼斯认为这将是太大
      在C语言中的改变...

The && and || operators were added later for their "short-circuiting" behavior. Dennis Ritchie admits in retrospect that the precedence of the bitwise operators should have been changed when the logical operators were added. But with several hundred kilobytes of C source code in existence at that point and an installed base of three computers, Dennis thought it would be too big of a change in the C language...

所以，这可能是一个原因？我猜，因为有按位precendence几层（不像关系比较），这是因为这是克鲁夫特存在...永远...，只是从来没有纠正。

So, that might be a reason? I'm guessing since there are several layers of bitwise precendence (unlike relational comparisons) that it's cruft that's existed since...forever...and just was never corrected.

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