[decimal] conversion has some unexpected behavior depending on culture settings

I ran into an issue where I had to convert a string value to decimal, to run a switch case on it. Once the systemlocale setting was set to en-US, there were no issues with the script, but when set to nl-NL (or any other country that uses a comma as seperator), it didn’t work as expected.

When you look at the world map and/or list of countries on Wikipedia, you’ll see that more countries use a comma as seperator than the ones that use a dot, but it seems that Microsoft only thought of their own default setting, but maybe neglected the rest?

I used this code:

As you can see in the result screenshot, the switch case won’t even run with numbers higher than 10, once there is a comma as decimal seperator. Because a 84,1 gets converted to 841 etc.
Small numbers get converted to a higher number as well (0.6 get changed to 6, 5.4 get changed to 54 etc.), but in my case, since I needed to check for percentages, they couldn’t be higher than 100.

If you want to test this script for yourself, I’ve added this line to the top of the script: [Threading.Thread]::CurrentThread.CurrentCulture = "nl-NL"
so you’ll be able to test it with a country that uses a comma as a seperator. You can use any other country as listed in the above wikipedia article, that uses a comma as decimal seperator and it should give the same result as the script I shared here. If you already live in a country that uses a comma as seperator, you can comment out the CurrentCulture line in the script.

You can download my sample script here.