C# 10 allows initializing 'const' strings using string interpolation, but the placeholder must also be a 'const' string.

The placeholder can't be a numeric constant cause it's converted to string at runtime.

Will you use the feature in your code?#dotnet #coding #devcommunity pic.twitter.com/H52ithdZC4

— Oleg Kyrylchuk (@okyrylchuk) September 9, 2021

Starting from C# 10, you can reference nested properties or fields within a proper pattern.

The property pattern becomes more readable and requires fewer curly brackets \U0001f642

What do you think about the feature? #dotnet #coding #devcommunity pic.twitter.com/iHmbdYUAOW

— Oleg Kyrylchuk (@okyrylchuk) September 10, 2021

C# 10 introduces a new way of namespace declarations - file scoped namespaces.

However, you cannot declare a nested namespace or a second file-scoped namespace in the same file.

C# continue to rid of curly brackets {\U0001f600}#dotnet #programming #devcommunity pic.twitter.com/docHOfZQYf

— Oleg Kyrylchuk (@okyrylchuk) September 11, 2021

C# 10 adds a new modifier to a 'using' directive - 'global'.

It means that 'using' is applied to all files in the compilation.

All 'global using' directives must be before non-global 'using' directives.

It can be combined with a 'static' modifier#dotnet #coding #devcommunity pic.twitter.com/osr3ZPh5AI

— Oleg Kyrylchuk (@okyrylchuk) September 12, 2021

In .NET 5, you can preserve references for circular references using System.Text.Json.

But you couldn't ignore them. The 'JsonException' is thrown if circular references have been detected.

In .NET 6, you can ignore them \U0001f642#dotnet6 #json #coding #devcommunity pic.twitter.com/FnvR8gjwvN

— Oleg Kyrylchuk (@okyrylchuk) October 6, 2021

In .NET 6, System.Text.Json exposes notifications for (de)serialization.

There are four new interfaces to implement according to your needs:
\u2022 IJsonOnDeserialized
\u2022 IJsonOnDeserializing
\u2022 IJsonOnSerialized
\u2022 IJsonOnSerializing#dotnet6 #json #coding #devcommunity pic.twitter.com/iYpzHsg8Hy

— Oleg Kyrylchuk (@okyrylchuk) October 7, 2021

In .NET 6, the 'JsonPropertyOrderAttribute' has been added to System.Text.Json.

It allows controlling the serialization order of properties.

Previously, the serialization order was determined by reflection order.#dotnet6 #json #coding #devcommunity pic.twitter.com/5sBJRWOvcX

— Oleg Kyrylchuk (@okyrylchuk) October 8, 2021

.NET 6 introduces the possibility to write 'raw' #json with System.Text.Json.Utf8JsonWriter.

Useful when you want:
\u2022 to enclose existing JSON in new JSON
\u2022 to format values differently from the default formatting#dotnet6 #coding #devcommunity pic.twitter.com/NguR3wEOAM

— Oleg Kyrylchuk (@okyrylchuk) October 16, 2021