Using an array in Powershell and trying to update it from multiple functions

Question

I have an array that is declared at the parent level.

I want to be able to use this array in multiple functions and I want to be able to update that array within those functions as needed (not adding to it, but modifying the values within the array).

I have tried declaring it as Global, but that does not seem to allow me to modify the data in the array.

Any help you can provide would be greatly appreciated.

Answer 1

Well, without seeing what those function do (i.e., you posting the code you've written) it's hard to say.

It's certainly possible to modify the contents of an array:

$a = 1,2,3  
function funca{  
    $a[1]=20  
}  
function funcb{  
    $a[2]=30  
}  
function funcc{  
    $a[0] = "Look, Ma! No hands!"  
}  
"--- unmodified array ---"  
$a  
funca  
funcb  
funcc  
"--- modified array ---"  
$a  

Answer 2

Arrays are annoying to use in PS. If you're not adding items to them then they should be fine. Here's a simplistic example.

   $items = @(1, 2, 3, 4)  
     
   function IncrementArray ( $arr )  
   {  
      for ($index = 0; $index -t $arr.length; ++$index) {  
         $arr[$index] *= 2  
      }  
   }  
     
   IncrementArray($items)  

Each time the function is called the elements in the array are doubled. To identify the array to modify you should pass it as a parameter to the function. This is the preferred approach.

If for some reason you don't want to pass the array to your functions then you should really reconsider your approach. But PS will find variables defined outside the function if the names aren't overridden inside the function. But this sets up functions that are not as reusable as you might hope.

Answer 3

$DBArray = @(  
            ("DBName","Sever", "Instance","DBPath","R01","R02","R03","R04","R05",$False,$False,$False,$False,$Fasle),  
            ("DB01","DEV-SRV01", "INSTDV01","BIN01","BR01","BR02","BR03","BR04","BR05",$False,$False,$False,$False,$Fasle),  
            ("DB02","DEV-SRV02", "INSTDV02","BIN02","CR01","CR02","CR03","CR04","CR05",$False,$False,$False,$False,$Fasle),  
            ("DB03","DEV-SRV03", "INSTDV03","BIN03","DR01","DR02","DR03","DR04","DR05",$False,$False,$False,$False,$Fasle))  
  
$FetchButton.Add_Click({ GoFetchRX $DBArray })  
  
function GoFetchRX {  
    Param ( $DBArray )  
  
    for ( $index = 0; $index -lt $DBArray.count; $index++)  
    {  
        Switch ($index)  
        {  
            0 {  
                #Do Nothing, This is the header  
            }  
              
            1 {  
                    if ($DBArray[$index][4] -ne "N/A")  
                    {  
                           $IsValCheck = CHECKRVAL $DBArray[$index][4]  
                           if(IsValCheck)  
                           {     $DBArray[$index][9]  = $True   
                           } else  
                           {     $DBArray[$index][9]  = $false  
                           }  
                    }  
              2 { .  
                   .  
                   .  
                  }  
          }  
}  
                               

There is a lot of code, So I tried to give something as close as I can.