Type Keywords

Microsoft Docs / Types Keywords

Recommendation

For locals, parameters and type members, prefer types that have a language keyword to represent them (int, double, string, etc.) to use that keyword instead of the type name (Int32, Int64, etc.).

Prefer the keyword whenever a member-access expression is used on a type with a keyword representation (int, double, string, etc.).

Justification

Both the Roslyn and .NET Core runtime teams agree that using this language feature is desirable.

The .NET Runtime Coding Style guidelines state:

We use language keywords instead of BCL types (e.g. int, string, float instead of Int32, String, Single, etc) for both type references as well as method calls (e.g. int.Parse instead of Int32.Parse).

Arguments

See this discussion between members of the .NET team for reference.

✔ Promotes consistency in coding style.

Performance

Benchmark code

Benchmark IL

Exceptions

Using type names in classes that deal with interop is acceptable.

Analyzers

Discussion

GitHub Discussion