Prefer 'null' check over type check (IDE0150)
| Property | Value |
|---|---|
| Rule ID | IDE0150 |
| Title | Prefer null check over type check |
| Category | Style |
| Subcategory | Language rules (expression-level preferences) |
| Applicable languages | C# |
| Options | csharp_style_prefer_null_check_over_type_check |
Overview
This style rule flags use of the is {type} statement when is not null can be used instead. Similarly, it flags use of the is not {type} statement in favor of is null. Using is null or is not null improves code readability.
Options
Options specify the behavior that you want the rule to enforce. For information about configuring options, see Option format.
csharp_style_prefer_null_check_over_type_check
| Property | Value | Description |
|---|---|---|
| Option name | csharp_style_prefer_null_check_over_type_check | |
| Option values | true |
Prefer null check over type check. |
false |
Disables the rule. | |
| Default option value | true |
Example
// Violates IDE0150.
if (numbers is not IEnumerable<int>) ...
// Fixed code.
if (numbers is null) ...
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 IDE0150
// The code that's violating the rule is on this line.
#pragma warning restore IDE0150
To disable the rule for a file, folder, or project, set its severity to none in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.IDE0150.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.
