Loops and Arrays (and some surprises)

Frequently, loops are used to retrieve (or generate) data, then save it to a variable. There can be tremendous performance differences though. To generate 10.000 random numbers, for example, you might look into something like this:

$numbers = @()

for ($x = 1 $x -le 10000 $x++) 
{
  $numbers += Get-Random -Minimum 1 -Maximum 7
}

$numbers.Count

It takes many seconds, and becomes almost paralyzing with even larger loop iterations.

Here is a similar approach that is many times faster:

Here is a similar approach that is many times faster:
$numbers = for ($x = 1 $x -le 10000 $x++) 
{
  Get-Random -Minimum 1 -Maximum 7
}

$numbers.Count

Instead of saving the results to a variable with each iteration, leave it to PowerShell to create and maintain the array. Just save the results of the loop when it is done.

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