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Deconstruct variable declaration (IDE0042)

  • Article
Property Value
Rule ID IDE0042
Title Deconstruct variable declaration
Category Style
Subcategory Language rules (expression-level preferences)
Applicable languages C#
Options csharp_style_deconstructed_variable_declaration

Overview

This style rule concerns the use of deconstruction in variable declarations, when possible.

Options

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

csharp_style_deconstructed_variable_declaration

Property Value Description
Option name csharp_style_deconstructed_variable_declaration
Option values true Prefer deconstructed variable declaration
false Do not prefer deconstruction in variable declarations
Default option value true 
// csharp_style_deconstructed_variable_declaration = true
var (name, age) = GetPersonTuple();
Console.WriteLine($"{name} {age}");

(int x, int y) = GetPointTuple();
Console.WriteLine($"{x} {y}");

// csharp_style_deconstructed_variable_declaration = false
var person = GetPersonTuple();
Console.WriteLine($"{person.name} {person.age}");

(int x, int y) point = GetPointTuple();
Console.WriteLine($"{point.x} {point.y}");

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 IDE0042
// The code that's violating the rule is on this line.
#pragma warning restore IDE0042

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

[*.{cs,vb}]
dotnet_diagnostic.IDE0042.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