枚举定义中的波浪号（〜）是多少？(What is the tilde (~) in the enum definition?)

枚举定义中的波浪号（〜）是多少？(What is the tilde (~) in the enum definition?)

我总是很惊讶，即使现在使用C＃后，我仍然设法找到我不知道的事情...

我已经尝试搜索互联网这个，但是在搜索中使用“〜”对我来说不是很好，我没有在MSDN上找到任何东西（不要说它不在那里）

我最近看到这段代码，波浪号（〜）是什么意思？

/// <summary> /// Enumerates the ways a customer may purchase goods. /// </summary> [Flags] public enum PurchaseMethod { All = ~0, None = 0, Cash = 1, Check = 2, CreditCard = 4 }

我有点惊讶地看到它，所以我试图编译它，它的工作...但我仍然不知道它的意思/做什么。 任何帮助？

I'm always surprised that even after using C# for all this time now, I still manage to find things I didn't know about...

I've tried searching the internet for this, but using the "~" in a search isn't working for me so well and I didn't find anything on MSDN either (not to say it isn't there)

I saw this snippet of code recently, what does the tilde(~) mean?

/// <summary> /// Enumerates the ways a customer may purchase goods. /// </summary> [Flags] public enum PurchaseMethod { All = ~0, None = 0, Cash = 1, Check = 2, CreditCard = 4 }

I was a little surprised to see it so I tried to compile it, and it worked... but I still don't know what it means/does. Any help??

最满意答案

〜是一元的补码运算符 - 它翻转其操作数的位。

~0 = 0xFFFFFFFF = -1

在二进制补码运算中， ~x == -x-1

〜操作符可以从C语言中找到，其中包括Objective-C / C ++ / C＃/ Java / Javascript。

~ is the unary one's complement operator -- it flips the bits of its operand.

~0 = 0xFFFFFFFF = -1

in two's complement arithmetic, ~x == -x-1

the ~ operator can be found in pretty much any language that borrowed syntax from C, including Objective-C/C++/C#/Java/Javascript.