dotnet-11

1.10m prints "1.10" because System.Decimal stores a scale alongside its digits, and arithmetic, parsing, and JSON all preserve it. How the scale is chosen, why 1.1m == 1.10m but their strings differ, three ways to strip trailing zeros (G29, a 0.## pattern, dividing by 1.000...m) and the 1E-05 trap in G29, how to force a fixed scale, and why .NET 11's double to decimal change produces digits no trick removes. Verified on .NET 10.0.14 and .NET 11 RC3.

Math.Round uses banker's rounding (MidpointRounding.ToEven) by default, so 2.5 rounds to 2 and 3.5 rounds to 4. How to get 'school' rounding with AwayFromZero, why Math.Round(2.675, 2) still gives 2.67, how .NET 11 changed Math.Round(double, digits) to round the exact binary value, and why ToString("F2") disagrees with decimal formatting. Verified on .NET 10.0.14 and .NET 11 RC3.

After SaveChangesAsync, EF Core 11 copies store-generated keys, defaults, computed columns and concurrency tokens back into your entities, fixes up foreign keys and navigations, and resets every entry to Unchanged. Here is exactly what gets written, when, what the SQL looks like, and four cases where the value on your entity is not what is in the database.

The October 25, 2026 out-of-band release (.NET 8.0.33, 9.0.22, 10.0.14, 11 RC3) fixes a Brotli buffer overflow, a Linux tarball ownership flaw, and two CVEs the October 13 patches did not fully close.

Model followers and following on a single User entity in EF Core 11: what the convention builds, why SQL Server quietly turns one join foreign key into ClientCascade, how to map an explicit Follow join entity with a timestamp, and how to delete a user without error 547 or 1785.

Microsoft.AspNetCore.OpenApi only marks a response nullable when the action returns a bare T? (and, on .NET 10, not even Task<T?>). ActionResult<T?> and IActionResult lose the annotation on both .NET 10 and .NET 11 RC2. Here is why, a tested operation transformer that fixes it, and the 204 No Content trap that makes the spec lie unless you also change MVC's formatter.

Use the en-IN culture or set NumberFormatInfo.NumberGroupSizes to [3, 2] to print 12,34,56,789 instead of 123,456,789 in C#. Measured on .NET 10 and .NET 11 RC1: how the array works, why CurrencyGroupSizes is separate, the invariant-globalization trap that silently prints Western grouping, and a lakh/crore words helper.

MapIdentityApi<TUser>() maps ten endpoints and has no switch to skip one. Here are four measured ways to deal with that on .NET 11: hide an endpoint from OpenAPI, make it return 404, shadow it, or remove it from routing entirely, plus the /confirmEmail trap that turns registration into a 500.

Understand C# reference escape rules with compiler-checked examples for ref locals, reassignment, scoped references and heap-backed versus stack-backed spans.

System.Formats.Cbor 11.0.0-rc.2 adds isFinalBlock, NeedsMoreData, and SlideData to CborReader, so you can decode CBOR straight off a stream without buffering the whole document. Verified on SDK 11.0.100-rc.2.