PowerShell 3.0 and later
PowerShell ISE already supports collapsible code regions. When you write functions, loops, or conditions, you will notice a vertical line in the left margin with a “minus” symbol on top. Click it to collapse the region.
If regions are missing, you may have to enable them: View/Show Outlining.
You can use regions and code folding for other parts of your script, too. To enclose an arbitrary part of your code in a collapsible region, put special comments into your code:
#region Variable Declarations $a = $b = $c = 1 $d, $e, $f = 2,3,4 #endregion
Note that these special comments are case sensitive. The text following “#region” becomes the title of the collapsible region once you collapse it.