String.CompareTo Behaviour different between WIN10 & Linux

[Ninds]

Console.WriteLine("[".CompareTo("_"));
On Windows => -1
On Linux => 1

Linux :
.NET Core SDK (reflecting any global.json):
Version: 3.1.201
Commit: b1768b4ae7

Runtime Environment:
OS Name: debian
OS Version: 10
OS Platform: Linux
RID: debian.10-x64

Host (useful for support):
Version: 3.1.3
Commit: 4a9f85e9f8

Windows :
.NET Core SDK (reflecting any global.json):
Version: 3.1.201
Commit: b1768b4ae7

Runtime Environment:
OS Name: Windows
OS Version: 10.0.17134
OS Platform: Windows
RID: win10-x64

Host (useful for support):
Version: 3.1.3
Commit: 4a9f85e9f8

[benaadams]

Different culture between the two? Try using .CompareOrdinal

Tagging subscribers to this area: @tarekgh, @safern, @krwq
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[tarekgh]

This is by design for the .NET as we depend on the underlying OS for globalization support. so it is expected to see some behavior differences when running on Windows against Linux. @benaadams suggestion to use ordinal comparison should help if this will be ok in your scenario.

In .NET Core 5.0, we have started to use the ICU library on Windows too. That means the behavior on Windows and Linux should be the same or very close. You may give it a try.

[Ninds]

Cheers. Tweaking the culture indeed yielded the required behaviour.