为什么没有|| =或放大器;＆安培; =运营商？ [英] Why are there no ||= or &&= operators?

问题描述

我们有相当的赋值运算符的所有逻辑运算符，移位运算，加法运算符和所有乘法运算。

为什么逻辑运算符被甩了呢？
是否有一个良好的技术原因，这是很难？

解决方案

  

为什么逻辑运算符被甩了呢？是否有一个良好的技术原因，这是很难？

他们没有。你可以做＆安培; = 或 | = 或 ^ = 如果你想。

  B1布尔= FALSE;
布尔B2 = TRUE;
B1 | = B2; //意味着B1 = B1 | B2
 

的 || 和＆放大器;＆安培; 运营商没有复合形式，因为坦率地说，他们是有点傻。在什么情况下你想说

  B1 || = B2;
B1和放大器;＆安培; = B2;
 

，使得如果左手侧不改变它的右手侧不评估？这似乎是只有少数人实际上使用该功能，那么，为什么把它？

有关复合经营者在这里看到我的认真文章：

<一个href=\"http://blogs.msdn.com/b/ericlippert/archive/2011/03/29/compound-assignment-part-one.aspx\">http://blogs.msdn.com/b/ericlippert/archive/2011/03/29/compound-assignment-part-one.aspx

和后续四月愚人文章在这里：

<一个href=\"http://blogs.msdn.com/b/ericlippert/archive/2011/04/01/compound-assignment-part-two.aspx\">http://blogs.msdn.com/b/ericlippert/archive/2011/04/01/compound-assignment-part-two.aspx

We have equivalent assignment operators for all Logical operators, Shift operators, Additive operators and all Multiplicative operators.

Why did the logical operators get left out? Is there a good technical reason why it is hard?

解决方案

Why did the logical operators get left out? Is there a good technical reason why it is hard?

They didn't. You can do &= or |= or ^= if you want.

bool b1 = false;
bool b2 = true;
b1 |= b2; // means b1 = b1 | b2

The || and && operators do not have a compound form because frankly, they're a bit silly. Under what circumstances would you want to say

b1 ||= b2;
b1 &&= b2;

such that the right hand side is not evaluated if the left hand side does not change? It seems like only a few people would actually use this feature, so why put it in?

For more information about the compound operators see my serious article here:

http://blogs.msdn.com/b/ericlippert/archive/2011/03/29/compound-assignment-part-one.aspx

and the follow-up April-Fools article here:

http://blogs.msdn.com/b/ericlippert/archive/2011/04/01/compound-assignment-part-two.aspx

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