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。
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...
The argument is null or empty. Provide an argument that is not null or empty, and then try the command again. CannotConnect,PSSessionStateBroken Cant access a fileshare through a remote PS Session Cant make work with variable in Get-ADuser command to get UPN Cant return string for msExchMa...
param( [Parameter(Mandatory)] [ValidateNotNullOrEmpty()] [string[]]$UserName ) ValidateNotNullOrWhiteSpace 驗證屬性 ValidateNotNullOrWhiteSpace 屬性指定指派的值不能是下列任何值: $null 空字串 ("") 空陣列 @() 只包含空格符的字串,例如製表符、空格、歸位字元和換行符 陣列,包含空字...
In this example, each object piped to the function is sent to theprocessstatement list. Theprocessstatements run on each object, one object at a time. The$inputautomatic variable is empty when the function reaches theendkeyword. PowerShell ...
If this parameter is omitted from the command, or it value is$nullor an empty string, the workflow target is the local computer and Windows PowerShell remoting is not used to run the command. To use an IP address in the value of theComputerNameparameter, the command must include thePSCred...
First positional function argument is: One Second positional function argument is: Two First named scriptblock argument is: One Second named scriptblock argument is: 4 通过此例来分析script 和function的关系。 Script由普通的Function以及其他的逻辑语句(顺序、选择、循环)组成。
The InformationAction parameter overrides, but doesn't replace the value of the $InformationAction preference variable when the parameter is used in a command to run a script or function. -InformationVariable Introduced in PowerShell 5.0. When you use the InformationVariable common parameter, informat...
ValidateNotNullOrEmpty ~Sean Thank you, Sean. You absolutely ROCK! Guest Blogger Week will continue tomorrow when Sean will bring us Part 7. I invite you to follow me onTwitterandFacebook. If you have any questions, send email to me atscripter@microsoft.com, or post your questions on the...
In other words, if[NullString]::Valuecould be passed to[string]parameters unaltered, the pain of$nullconversion to[string]::emptycould be managed once where the parameter is created (or at the module boundary) rather than at every possible site where such a parameter might be passed to a ...