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Simplify 'default' expression (IDE0034)

  • Article
Property Value
Rule ID IDE0034
Title Simplify default expression
Category Style
Subcategory Language rules (expression-level preferences)
Applicable languages C#
Options csharp_prefer_simple_default_expression

Overview

This style rule concerns using the default literal for default value expressions when the compiler can infer the type of the expression.

Options

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

csharp_prefer_simple_default_expression

Property Value Description
Option name csharp_prefer_simple_default_expression
Option values true Prefer default over default(T)
false Prefer default(T) over default
Default option value true 
// csharp_prefer_simple_default_expression = true
void DoWork(CancellationToken cancellationToken = default) { ... }

// csharp_prefer_simple_default_expression = false
void DoWork(CancellationToken cancellationToken = default(CancellationToken)) { ... }

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.

#pragma warning disable IDE0034
// The code that's violating the rule is on this line.
#pragma warning restore IDE0034

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

[*.{cs,vb}]
dotnet_diagnostic.IDE0034.severity = none

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

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

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

See also