$str4=" "if($str4-match"^\s*$") {Write-Host"String is empty"}else{Write-Host"String is not empty"} 输出: String is empty
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...
$string=""if($string) {Write-Host"The variable is not null."}else{Write-Host"The variable is null." } Output: The variable is null. White space characters are not considered null string values. Use theIsNullorEmptyMethod to Check if a String Variable Is Not Null or Empty in PowerShell...
除了Trim()函数,还可以使用TrimStart()函数和TrimEnd()函数分别删除字符串开头和结尾的空字符。 代码语言:txt 复制 $trimmedStartString = $originalString.TrimStart() $trimmedEndString = $originalString.TrimEnd() 这些函数可以帮助我们在PowerShell中处理字符串时避免空字符带来的问题,确保数据的准确性和一致性。
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 。
ValidateNotNullOrEmptyAttribute:限制变量不等为空,不能为空字符串,不能为空集合 ValidatePatternAttribute:限制变量要满足制定的正则表达式 ValidateRangeAttribute:限制变量的取值范围 ValidateSetAttribute:限制变量的取值集合 ValidateNotNullAttribute 例子 ValidateNotNullOrEmptyAttribute 例子,注意@()为一个空数组。
類型:String<empty string>從本課程模組導出之命令的預設前置詞。 使用Import-Module -Prefix覆寫預設前置詞。 範例:DefaultCommandPrefix = 'My' 範例模組指令清單 PowerShell複製 關於_比較_運算符 關於_如果 全域程式集緩存 Import-Module New-ModuleManifest ...
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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. ...
PowerShell 7.0 引進了三元運算子,其行為類似簡化的if-else陳述式。 PowerShell 的三元運算子會根據 C# 三元運算子語法嚴密地進行模型化: <condition> ? <if-true> : <if-false> 條件運算式一律會進行評估,並將結果轉換成布林值,以判斷下一個要評估的分支: ...