As a consultant I move from project to project, usually meeting a bunch of new people each time, imparting some wisdom, and moving on. One of the highlights for me is what I learn from the people that I encounter along the way.

And so it was that I met Neil East in Canberra, and he shared with me his amazing PowerShell code toggle.

The point of this is that it’s a MIND-BOGGLINGLY simple way of replacing a line (or more) of a script with an alternative. Typically this is when you’re developing and might want to run some code in a “read only” mode, or some other debugging process, and you might have a need to toggle back and forth many times.

Neil’s trick exploits that PowerShell has two different ways of commenting-out code:

The most common is just starting a line with a “#”.

# This line won't be actioned

The other is to wrap one or more lines in a “<#" and a "#>“.

<# This will be skipped too #>

Neil’s trick uses both, and all you need to do is delete the first “<” – shown highlighted below – to activate the second chunk of code.

<# 
    Write-host "that"
<#>
    Write-host "this"
#>

If you paste the above into a PowerShell window it will report “this”.

Here’s the same code, minus the first “<“, and if you run it now you’ll see it reports “that”:

# 
    Write-host "that"
<#>
    Write-host "this"
#>

 
I think it’s amazing, and Neil kindly gave me permission to share it. Enjoy. (Thanks Neil.)

 
– Greig.