Checking if a string is NULL or EMPTY is very common requirement in Powershell script. If we don’t do that we will end up with run time errors if we try to perform some operation on that string variable which i
IsNotNullOrEmpty如果值是字串,您可以使用靜態字串函式來檢查值是否為 $null 或同時為空字串。PowerShell 複製 if ( -not [string]::IsNullOrEmpty( $value ) ){...} 當我知道實值類型應該是字串時,我經常會使用這個 。當我檢查 $null 時我是一個防禦腳本手。 每當我呼叫函式並將它指派給變數時,我...
function Test-MrParameterValidation { [CmdletBinding()] param ( [ValidateNotNullOrEmpty()] [string[]]$ComputerName = $env:COMPUTERNAME ) Write-Output $ComputerName } 详细输出 如果要编写复杂的代码,则内联注释非常有用,但除非用户查看代码,否则不会看到它们。 以下示例中的函数在 foreach 循环内有一...
[-Path] <String[]> [-Filter <String>] [-Include <String[]>] [-Exclude <String[]>] [-Force] [-Credential <PSCredential>] [-Delimiter <String>] [-Wait] [-Raw] [-Encoding <Encoding>] [-AsByteStream] [-Stream <String>] [<CommonParameters>] 三、参数详解 -ReadCount:设置每次通过管道...
$string="Hello World" The following example checks if a$stringvariable is null or not in PowerShell. It returns the first statement if the variable is not null or empty and the second statement if the variable is null or empty. if($string) {Write-Host"The variable is not null."}else...
Passing$nullto any of these functions outputs$null. The only parameter type I haven't found a way to which to pass$nullwithout conversion is[string]; PowerShell always converts$nullto[string]::Empty. PowerShell's behavior in this regard is also inconsistent with C#. The corresponding functio...
When the command is invoked, this value will get bound to positional parameter 0 of the "select-object" cmdlet which is "Property". AddCommand(CommandInfo) CommandInfo object for the command to add. AddCommand(String, Boolean) Add a cmdlet to construct a command pipeline. For example, to...
如果需要参数有多个值,指定类型为string[] functionTest-MrParameterValidation { [CmdletBinding()]param( [Parameter(Mandatory)] [string[]]$ComputerName) Write-Output$ComputerName} 如果需要指定一个默认参数需要将ValidateNotNullOrEmpty参数验证属性与默认值一起使用,不过不能与必需(Mandatory)参数一起使用!
function Get-FunctionPosition { [CmdletBinding()] [OutputType('FunctionPosition')] param( [Parameter(Position = 0, Mandatory, ValueFromPipeline, ValueFromPipelineByPropertyName)] [ValidateNotNullOrEmpty()] [Alias('PSPath')] [System.String[]] $Path ) process { try { $filesToProcess = if (...
string to System.Management.Automation.ScriptBlock Cannot use Set-Acl properly despite being file owner and being a member of Administrators Group. Cannot validate argument on parameter 'Name'. The argument is null or empty. Provide an argument that is not null or empty, and then try the ...