windows 如何否定 PowerShell 中的条件？
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How do I negate a condition in PowerShell?
提问by Ben McCormack
How do I negate a conditional test in PowerShell?
如何在 PowerShell 中否定条件测试？
For example, if I want to check for the directory C:\Code, I can run:
例如，如果我想检查目录 C:\Code，我可以运行：
if (Test-Path C:\Code){
write "it exists!"
}
Is there a way to negate that condition, e.g. (non-working):
有没有办法否定这种情况，例如（非工作）：
if (Not (Test-Path C:\Code)){
write "it doesn't exist!"
}
Workaround:
解决方法：
if (Test-Path C:\Code){
}
else {
write "it doesn't exist"
}
This works fine, but I'd prefer something inline.
这很好用，但我更喜欢内联的东西。
回答by Rynant
You almost had it with Not. It should be:
你几乎拥有它Not。它应该是：
if (-Not (Test-Path C:\Code)) {
write "it doesn't exist!"
}
You can also use !: if (!(Test-Path C:\Code)){}
您还可以使用!：if (!(Test-Path C:\Code)){}
Just for fun, you could also use bitwise exclusive or, though it's not the most readable/understandable method.
只是为了好玩，您也可以使用按位互斥，或者虽然它不是最易读/易理解的方法。
if ((test-path C:\code) -bxor 1) {write "it doesn't exist!"}
回答by Steven Penny
回答by ZEE
Powershell also accept the C/C++/C* not operator
Powershell 也接受 C/C++/C* not 运算符
if ( !(Test-Path C:\Code) ){ write "it doesn't exist!" }
if ( !(Test-Path C:\Code) ){ 写“它不存在！” }
I use it often because I'm used to C*...
allows code compression/simplification...
I also find it more elegant...
我经常使用它是因为我习惯了 C*...
允许代码压缩/简化...
我也发现它更优雅...
回答by Melchior Kannengie?er
if you don't like the double brackets or you don't want to write a function, you can just use a variable.
如果你不喜欢双括号或者你不想写一个函数，你可以只使用一个变量。
$path = Test-Path C:\Code
if (!$path) {
write "it doesn't exist!"
}
