Collection was modified; enumeration operation may not execute Delete all libraries

Question

I need to delete all libraries from a subsite, however I got this error:

Collection was modified; enumeration operation may not execute



$web = Get-SPweb($webUrl)


  foreach($list in $web.Lists) {
    if($list.BaseType -eq "DocumentLibrary")
    {
        write-host $list.BaseType
       $list.Delete

    }
  }

Answer 1

You get this error because you're deleting straight from your source collection, which will change as soon as you start deleting.

A possible solution is to first get all the lists you wish to delete and store them in a seperate list (not subject to modification, since this is not the source collection)

$listsToDelete = @()

foreach($list in $web.Lists) {
    if($list.BaseType -eq "DocumentLibrary")
    {
        $listsToDelete += $web.Lists[$list.Title]
    }
}

foreach($listToDelete in $listsToDelete) {
    $listToDelete.Delete()
}

Answer 2

Below also works

$web = Get-SPweb($webUrl)
  foreach($i in (0..($web.Lists.length-1))){
    if($web.Lists[$i].BaseType -eq "DocumentLibrary"){
        write-host $web.Lists[$i].BaseType
       $web.Lists[$i].Delete
    }
  }