== VS等于C＃

问题描述

是什么==评价之间的差异，在C＃等于？

有关防爆，

 如果（X == X ++）//始终返回true，
  

但

 如果（x.Equals（X ++））//始终返回false 
  

编辑：

  INT X = 0; 
 INT Y = 0; 
 
如果（x.Equals（Y ++））//返回True 
  

解决方案

根据规范，这是预期的行为。

第一次的行为是规范的7.3节管辖。

操作数从左至右进行评价。例如，在 F（I）+ G（我+ +）* H（I），方法F使用我的旧值被调用，那么方法G称为与我的旧值，并且，最后，方法H称为与i的新值。在这是独立且无运算符优先级。






因此​​Y == X ++ ，第一左操作数进行评估（ 0 ），然后右手被评估（ 0 ， X 变成 1 ），则比较完成： 0 == 0 是真的

第二的行为是由部分7.5.5决定：

Thus in x==x++, first the left operand is evaluated (0), then the right-hand is evaluated (0, x becomes 1), then the comparison is done: 0 == 0 is true.

The behavior of the second is governed by section 7.5.5:

Note that value types are passed by reference to their own methods.

Thus in x.Equals(x++), first the target is evaluated (E is x, a variable), then the arguments are evaluated (0, x becomes 1), then the comparison is done: x.Equals(0) is false.

EDIT: I also wanted to give credit to dtb's now-retracted comment, posted while the question was closed. I think he was saying the same thing, but with the length limitation on comments he wasn't able to express it fully.

这篇关于== VS等于C＃的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！