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Use conditional expression for assignment (IDE0045)

  • Article
Property Value
Rule ID IDE0045
Title Use conditional expression for assignment
Category Style
Subcategory Language rules (expression-level preferences)
Applicable languages C# and Visual Basic
Introduced version Visual Studio 2017
Options dotnet_style_prefer_conditional_expression_over_assignment

Overview

This style rule concerns the use of a ternary conditional expression versus an if-else statement for assignments that require conditional logic.

Options

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

dotnet_style_prefer_conditional_expression_over_assignment

Property Value Description
Option name dotnet_style_prefer_conditional_expression_over_assignment
Option values true Prefer assignments with a ternary conditional
false Prefer assignments with an if-else statement
Default option value true 
// dotnet_style_prefer_conditional_expression_over_assignment = true
string s = expr ? "hello" : "world";

// dotnet_style_prefer_conditional_expression_over_assignment = false
string s;
if (expr)
{
    s = "hello";
}
else
{
    s = "world";
}

' dotnet_style_prefer_conditional_expression_over_assignment = true
Dim s As String = If(expr, "hello", "world")

' dotnet_style_prefer_conditional_expression_over_assignment = false
Dim s As String
If expr Then
    s = "hello"
Else
    s = "world"
End If

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 IDE0045
// The code that's violating the rule is on this line.
#pragma warning restore IDE0045

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

[*.{cs,vb}]
dotnet_diagnostic.IDE0045.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