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 is empty or null. So the question now is, how to check it? Well, belo...
PowerShell 複製 if ( $null -ne $value -and $value -ne 0 -and $value -ne '' -and ($value -isnot [array] -or $value.Length -ne 0) -and $value -ne $false ) { Do-Something } 只要您記得其他值算作$false,而不僅僅是變數具有值,使用基本if檢查就完全沒問題了。
Check if HyperThreading is enabled Check if IIS running on a remote server check if object is $null Check if OS is 32bit or 64bit check If Process Is Running in another computer Check if SMB1 is enabled on the AD servers Check if string contains invalid characters Check if string star...
functionTest-MrParameterValidation{ [CmdletBinding()]param( [Parameter(Mandatory)] [string[]]$ComputerName)Write-Output$ComputerName} 如果没有指定ComputerName参数,也许要为其指定一个默认值。 问题是,默认值不能与强制性参数一起使用。 取而代之的是使用带有默认值的ValidateNotNullOrEmpty参数验证属性。
特性的值HelpMessage不应为空字符串或 null 值,因为这会导致 PowerShell 解释器在执行函数或 cmdlet 时引发错误。 方式 指定HelpMessage属性的值。 示例 错 PowerShell FunctionBadFuncEmptyHelpMessageEmpty {Param( [Parameter(HelpMessage='')] [String]$Param)$Param}FunctionBadFuncEmptyHelpMessage...
If the function is invoked without pipeline input, PowerShell executes theprocessblock only once. Within a pipeline, theprocessblock executes once for each input object that reaches the function. If the pipeline input that reaches the function is empty, theprocessblock doesn't execute. ...
If you simply remove the[string]type then it will work as expected: function f2 { param ( $x ) return $x } $null -eq (f2 -x $null) There is no value in declaring a parameter as type string because all classes in .Net have to derive from theObjectclass. Therefore every class impl...
Commands Gets or sets current powershell command line. HadErrors If an error occurred while executing the pipeline, this will be set to true. HistoryString The history string to be used for displaying the history. InstanceId Get unique id for this instance of runspace pool. It is primarily...
If Format is not specified, it is inferred from the file extension of ArchiveFileName (#24, proposed by @onyxhat) Added new parameter VolumeSize to specify the colume size for Compress-7Zip (#25, proposed by @rgel) Added new switches FlattenDirectoryStructure, SkipEmptyDirectories, and Disab...
Returns:"Write-ErrorMessage : Expired or Invalid pagination request. Default Expiry time is 00:30:00" But if you use the Customer's.onmicrosoft.comdomain it works. If you use the Customer's Primary Domain Name (which is often the onmicrosoft domain, but is sometimes ...