Simplify new expression (IDE0090)

Property	Value
Rule ID	IDE0090
Title	Simplify new expression
Category	Style
Subcategory	Language rules (expression-level preferences)
Applicable languages	C# 9.0+
Options	csharp_style_implicit_object_creation_when_type_is_apparent

Overview

This style rule concerns the use of C# 9.0 target-typed new expressions when the created type is apparent.

Options

Options specify the behavior that you want the rule to enforce. For information about configuring options, see Option format.

csharp_style_implicit_object_creation_when_type_is_apparent

Property	Value	Description
Option name	csharp_style_implicit_object_creation_when_type_is_apparent
Option values	true	Prefer target-typed new expressions when created type is apparent
	false	Do not prefer target-typed new expressions
Default option value	true

C#

// csharp_style_implicit_object_creation_when_type_is_apparent = true
C c = new();
C c2 = new() { Field = 0 };

// csharp_style_implicit_object_creation_when_type_is_apparent = false
C c = new C();
C c2 = new C() { Field = 0 };

Suppress a warning

If you want to suppress only a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

C#

#pragma warning disable IDE0090
// The code that's violating the rule is on this line.
#pragma warning restore IDE0090

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

ini

[*.{cs,vb}]
dotnet_diagnostic.IDE0090.severity = none

To disable all of the code-style rules, set the severity for the category Style to none in the configuration file.

ini

[*.{cs,vb}]
dotnet_analyzer_diagnostic.category-Style.severity = none

For more information, see How to suppress code analysis warnings.

See also

• Target-typed new expressions
• Code style language rules
• Code style rules reference