This tutorial will introduce different methods to check if a string is not null or empty in PowerShell.
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 ( $PSBoundParameters.ContainsKey('Value') ){...} 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 。
Write-Host "Variable is null" } Here, if block checks if variable has a truthy value, so it will go to elseif block even if value is 0, $false, an empty String, an empty array, and not just $null, and that’s the reason, we have put explicit check in elseif statement if vari...
如果需要参数有多个值,指定类型为string[] functionTest-MrParameterValidation { [CmdletBinding()]param( [Parameter(Mandatory)] [string[]]$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!
Please note that while checking if array contains any element, it also check for its datatype. Mixed data types 1 2 3 4 5 $myArray=42,"PowerShell",$true,19.99 $item="42" $result=$myArray.Contains($item) Here, $result will be $false because "42" (string) is not the same type ...
functionTest-MrParameterValidation{ [CmdletBinding()]param( [Parameter(Mandatory)] [string[]]$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。
GitHub Discussions is a feature to enable free and open discussions within the community for topics that are not related to code, unlike issues. This is an experiment we are trying in our repositories, to see if it helps move discussions out of issues so that issues remain actionable by the...
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 ...