Arrays and loops

• The while loop repeats a block while the condition evaluates to true:

  $command = ""
  while($command.ToLower() -NotMatch "quit" –and $command.ToLower() -NotMatch "q")
  {
     $command = Read-Host "Enter your command >"
  }

• The for loop repeats for a predefined number of iterations:

  for($counter = 0; $counter -lt 10; $counter++)
  {
      Write-Verbose "Processing item $counter"
  }

• The Foreach loop repeats for all items in the collection:

  $processes = (Get-Process | Where CPU -gt 30)
  foreach($process in $processes)
  {
    Write-Verbose "$($process.ProcessName):$($process.CPU)"
  }

  Note that this Foreach loop can be rewritten as:

  Get-Process | Where CPU -gt 30 |
  Foreach {
     Write-Verbose "$($_.ProcessName) : $($_.CPU)"
  }