运行if语句时,PowerShell 会将<test1>条件表达式计算为 true 或 false。 如果<test1>为 true,<statement list 1>则运行,PowerShell 退出 语句if。 如果<test1>为 false,则 PowerShell 将计算条件语句指定的<test2>条件。 有关布尔计算的详细信息,请参阅about_Booleans。
This correctly outputs “Valid”. If I change $value to a non-integer, it correctly outputs “Invalid” when I run the above code. All fine and good. However, if I only want to check and run code for invalid integers (doing nothing for valid ones), the following IF statement returns ...
If $process gets assigned a value, then the statement is $true and $process gets stopped. Make sure you don't confuse this with -eq because this isn't an equality check. This is a more obscure feature that most people don't realize works this way. Variable assignment from the scriptblo...
ERROR: Variable: found in expression: is not defined. ERROR:Cannot process argument transformation on parameter 'DriveLetter'. Cannot convert value "$DriveLetter" to type "System.Char". Error: "String must be exactly one character long." escape the single quote inside an insert statement Escapi...
# This statement returns true because book contains the string "oo" 'book' -match 'oo' 字元類別雖然字元常值可運作,但如果您知道確切的模式,字元類別可讓您較不明確。字元群組[character group] 可讓您一次比對任意數目的字元,而 [^character group] 只比對群組中的字元 NOT。PowerShell...
删除变量:Clear-Variable -Name var或者clv var 查看变量类型:$var.GetType() 作用域:$[<scope-modifier>:]<name> = <value> 自动变量[5] 常用自动变量 $?:上一次执行成功。成功返回True $$:返回上一个指令的最后一个令牌(token) $^:返回第一个token ...
In this example, each object piped to the function is sent to theprocessstatement list. Theprocessstatements run on each object, one object at a time. The$inputautomatic variable is empty when the function reaches theendkeyword. PowerShell ...
This command uses an array of character strings as input to the Variable parameter. The array defines multiple SQLCMD variables. The $ signs in the SELECT statement that identify the SQLCMD variables are escaped using the back-tick (`) character. ...
Nested PowerShell is used to do simple operations like checking state of a variable while another command is using the runspace. Nested PowerShell should be invoked from the same thread as the parent PowerShell invocation thread. So effectively the parent Powershell invocation thread is blocked ...
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