Use 'is null' check (IDE0041)
Property | Value |
---|---|
Rule ID | IDE0041 |
Title | Use 'is null' check |
Category | Style |
Subcategory | Language rules (expression-level preferences) |
Applicable languages | C# and Visual Basic |
Introduced version | Visual Studio 2017 |
Options | dotnet_style_prefer_is_null_check_over_reference_equality_method |
Overview
This style rule concerns the use of a null check with pattern matching versus the use of the equality operator (==
) or calling Object.ReferenceEquals(Object, Object).
Options
Options specify the behavior that you want the rule to enforce. For information about configuring options, see Option format.
dotnet_style_prefer_is_null_check_over_reference_equality_method
Property | Value | Description |
---|---|---|
Option name | dotnet_style_prefer_is_null_check_over_reference_equality_method | |
Option values | true |
Prefer is null check |
false |
Prefer reference equality method | |
Default option value | true |
// dotnet_style_prefer_is_null_check_over_reference_equality_method = true
if (value is null)
return;
// dotnet_style_prefer_is_null_check_over_reference_equality_method = false
if (object.ReferenceEquals(value, null))
return;
// dotnet_style_prefer_is_null_check_over_reference_equality_method = false
if ((object)o == null)
return;
' dotnet_style_prefer_is_null_check_over_reference_equality_method = true
If value Is Nothing
Return
End If
' dotnet_style_prefer_is_null_check_over_reference_equality_method = false
If Object.ReferenceEquals(value, Nothing)
Return
End If
' dotnet_style_prefer_is_null_check_over_reference_equality_method = false
If CType(value, Object) = Nothing
Return
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 IDE0041
// The code that's violating the rule is on this line.
#pragma warning restore IDE0041
To disable the rule for a file, folder, or project, set its severity to none
in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.IDE0041.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
Phản hồi
https://aka.ms/ContentUserFeedback.
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