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...
if ( $value -eq $null ) { 'The array is $null' } if ( $value -ne $null ) { 'The array is not $null' } 如果我未定義 $value,那麼第一個評估為 $true,而我們的訊息為 The array is $null。 這裡的陷阱是有可能創建一個 $value,這允許兩者都可以成為 $falsePowerShell 複製 ...
Now you might get a question, what if the $mystring has white space as value. It is neither a EMPTY value nor a NULL value so we can not use IsNullOrEmpty() method in this case. If you try it, it will return False which means string is not NULL or EMPTY. In such cases we can...
if( (Get-Process)-and(Get-Service) ) 檢查$null 在語句中沒有結果或$null值評估為$falseif。 特別$null檢查 時,最佳做法是將 放在$null左側。 PowerShell if($null-eq$value) 處理PowerShell 中的值時$null,有相當多的細微差別。 如果你有興趣深入潛水,我有一篇文章,關於你想知道的一切$null。
[datetime]::Now'MinValue','MaxValue'|ForEach-Object{ [int]::$_} 三元运算符? <if-true> : <if-false> 在简单的条件情况下,可以使用三元运算符替代if-else语句。 有关详细信息,请参阅about_If。 Null 合并操作符?? 如果null 合并运算符??不为 null,则它返回其左操作数的值。 否则,它将计算右操...
Let’s assign an empty string value to a variable and check again. If a variable is not assigned, it also has a null value. $string=""if($string) {Write-Host"The variable is not null."}else{Write-Host"The variable is null." ...
$Env:<variable-name> ="<new-value>" 例如,若要创建环境变量,请执行以下操作Foo: PowerShell复制 $Env:Foo='An example' 由于环境变量始终是字符串,因此可以像使用包含字符串的任何其他变量一样使用它们。 例如: PowerShell复制 "The 'Foo' environment variable is set to:$Env:Foo"$Env:Foo+='!'$E...
if ($ver.Version.Major -gt 1) {$Host.Runspace.ThreadOptions = "ReuseThread"} Add-PsSnapin Microsoft.SharePoint.PowerShell Set-location $home # Check that this is a command-line interface and not the ISE if ($host.name -eq "ConsoleHost") { $width = 80 $sizeWindow = new-object ...
By default, this parameter is blank ($null), which allows this recipient to accept messages from all groups. Expand table Type: MultiValuedProperty Position: Named Default value: None Required: False Accept pipeline input: False Accept wildcard characters: False Applies to: Exchange Server 2010...
"@Send-MailMessage@emailConfig-Body$emailBody}try{# Create a timestamp for the current execution$timestamp=Get-Date-Format"yyyy-MM-dd HH:mm:ss"# Write timestamp to the log fileAdd-Content-Path$logFile-Value"Execution timestamp:$timestamp"# Check if log fi...