从PowerShell中的2个变量创建一个增量变量

Question

好的，首先，我认为自己是新手，并且有很多了解PowerShell，这是我有史以来的第一篇文章。 我正在尝试循环浏览一些数据，并将其放入自定义对象中，并将它们放入单独的数组以供以后使用。问题是我想通过使用计数器$ i创建一个代表$ Week_data1的变量，以便可以减少所需的代码量。我确实有一个串联的变量正在写出：写入host'$ Week ++ ='$ Week $ i，但我认为它被表示为字符串吗？ 我如何获得$ Week_data $ i代表插入数据的数组？

Input data. Each week ends on Saturday.
    $week1=@('2021-05-01')
    $week2=@('2021-05-02', '2021-05-03', '2021-05-04', '2021-05-05', '2021-05-06', '2021-05-07', '2021-05-08')
    $week3=@('2021-05-09', '2021-05-10', '2021-05-11', '2021-05-12', '2021-05-13', '2021-05-14', '2021-05-15')
    $week4=@('2021-05-16', '2021-05-17', '2021-05-18', '2021-05-19', '2021-05-20', '2021-05-21', '2021-05-22')
    $week5=@('2021-05-23', '2021-05-24', '2021-05-25', '2021-05-26', '2021-05-27', '2021-05-28', '2021-05-29')
    $week6=@('2021-05-30', '2021-05-31')
    $month =@($week1, $week2, $week3, $week4, $week5, $week6) 
    
Create the output structures to be populated.
    $week_data1=@()
    $week_data2=@()
    $week_data3=@()
    $week_data4=@()
    $week_data5=@()
    $week_data6=@()
    $month_data =@($week_data1, $week_data2, $week_data3, $week_data4, $week_data5, $week_data6)
Loop through the array and count the week number that is being processed.

    $i = 0
    foreach($week in $month)
    { $i++
    $n=0

Here I can write out a Variable and it concatenates properly.
    **write-host '$week++ ='$week$i**
        foreach($day in $week)
        {$n++
        write-host '$day ='$day
Pull in data from a .csv file to populate the custom object.
        foreach($line in $csv) 
         {
          if($line -match $day)
Match the line in the CSV file that has the correct Date in it. One line in the file per date in the month.
          { #write-host '$line.Day = ' $line.Day
            # custom object to be used later 
            $date_data = [PSCustomObject] @{
             week_numb = $i
             date = $line.Day
             attempts = $line.Attempts
             connects = $line.Connects
            }
I have tried different syntax versions but it does not work here? I want to put the custom object data into the new array for the week being processed. 
          #write-host '$week_data[$i]='$week_data[$i]
          $week_data$i += $date_data # Add data from csv file into a 
          #$week_data[$i] += $date_data
          }
         }
    
        }
    }

使用$ Week_data $ i作为变量我会出现错误：

在行：38 char：17

•   $ Week_data $ i += $ date_data＃将CSV文件中的数据添加到一个
   

•   ~~
   

表达式或语句中意外的令牌“ $ i”。 + categoryInfo：parserError：{:) []，parentContainsRorrecordException +完全QualififiedErrid：意外情况

Answer 1

您正在寻找变量间接，即可以通过存储在另一个变量中或从表达式中返回的名称间接地引用变量的能力。

但是请注意，通常有优越的替代方案，例如使用阵列或 Hashtables 作为Multi -Value容器 - 请参见示例。

如果您确实需要使用可变间接方向，请使用 get-variable 和 set-variable ：

$week_data1 = 'foo', 'bar'

$i = 1

# Same as: $week_data1
# Note that "$" must NOT be specified as part of the name.
Get-Variable "week_data$i" -ValueOnly

# Same as: $week_data1 = 'baz', 'quux'
Set-Variable "week_data$i" baz, quux

# Updating an existing value requires nesting the two calls:
# Same as: $week_data1 += 'quuz'
Set-Variable "week_data$i" ((Get-Variable "week_data$i" -ValueOnly) + 'quuz')

作为旁边：“扩展”具有+=的数组很方便，但效率低下：a new 必须每次在场景后面创建 - 请参见此答案。

同样，与直接分配和变量引用相比，调用 cmdlet 进行设置和获取变量的性能差。

请参阅此答案使用 emoverencome embocore 变量，使用get-get-get-get-- content/set-content和env：驱动器。

---

至于您尝试过的：

• $ week_data $ i = ...是一个分配 expression ，它被解释为直接并列<< em>两个变量，$ Week_data和$ i，这会导致您看到的 andtax错误您看到的。

• 相比之下，类似书面输出$ Week_data $ i是命令，而$ Week_data $ i也被解释为两个变量引用，作为a 命令参数它在句法上有效，只需通过两个变量值的（stringified） conmanation ;换句话说：$ WEEK_DATA $ i表现得好像是双重引用的，即AN a>，因此命令等效于写出“ $ Week_data $ i”

  
  

Answer 2

与答案无关，但可能对您有所帮助，我的功能将确定给定日期一个月的哪一周。

Function Get-Week{
[cmdletbinding()]
param([parameter(ValueFromPipeline)][string[]]$Date)
process{
    ForEach($Day in $Date){
        $DTDay=[datetime]$Day
        $Buffer = ([datetime]("{0}-01-{1}" -f $DTDay.Month,$DTDay.Year)).dayofweek.value__ -1 
        [math]::Truncate(($DTDay.Day+$Buffer)/7)+1
    }
}
}

因此，您可以将可以转换为类似日期的字符串喂食：

'5-13-2021' | Get-Week

或者

Get-Week '5-13-2021'

您会收回一个指示当天月份（周六结束）的数字。