This tutorial will introduce different methods to check if a string variable is not null or empty in PowerShell. Use a Conditional Statement to Check if a String Variable Is Not Null or Empty in PowerShell We h
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...
if($PSBoundParameters.ContainsKey('Value') ){...} IsNotNullOrEmpty 如果值为字符串,则可以同时使用静态字符串函数来检查值为$null还是空字符串。 PowerShell if(-not[string]::IsNullOrEmpty($value) ){...} 当我知道值类型应该是字符串时,我经常使用此值。
function Test-MrParameterValidation { [CmdletBinding()] param ( [Parameter(Mandatory)] [string[]]$ComputerName ) Write-Output $ComputerName } 如果没有指定 ComputerName 参数,也许要为其指定一个默认值。问题是,默认值不能与强制性参数一起使用。 取而代之的是使用带有默认值的 ValidateNotNullOrEmpty ...
如果需要参数有多个值,指定类型为string[] functionTest-MrParameterValidation { [CmdletBinding()]param( [Parameter(Mandatory)] [string[]]$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!
新增-NoEmphasize 參數以 Select-String 輸出 (#8963) (感謝 @derek-xia!) 重新新增 Get-HotFix Cmdlet (#10740) 讓Add-Type 可用於裝載 PowerShell 的應用程式中 (#10587) 在LanguagePrimitives.IsNullLike () (#10781 中使用更有效率的評估順序,) (感謝 @vexx32!) ...
); } //提供一个对话框,允许用户从一组选项中选择一个选项 public override int PromptForChoice(string caption, string message, System.Collections.ObjectModel.Collection<ChoiceDescription> choices, int defaultChoice) { throw new NotImplementedException("PromptForChoice is not implemented. The script is ...
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 ...
all we’re doing here is assigning a value to a variable named $yes. Note that you can name this variable anything you want; it doesnothave to have the same name as the option. Even though we’re setting up a Yes option we could have named the variable $watermelon if we wanted to...
ERROR: The term <tool-name> is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again. If the remote computer is running a 64-bit version ...