Use index operator (IDE0056)
Property | Value |
---|---|
Rule ID | IDE0056 |
Title | Use index operator |
Category | Style |
Subcategory | Language rules (expression-level preferences) |
Applicable languages | C# 8.0+ |
Options | csharp_style_prefer_index_operator |
Overview
This style rule concerns the use of the index-from-end operator (^
), which is available in C# 8.0 and later.
Options
Options specify the behavior that you want the rule to enforce. For information about configuring options, see Option format.
csharp_style_prefer_index_operator
Property | Value | Description |
---|---|---|
Option name | csharp_style_prefer_index_operator | |
Option values | true |
Prefer to use the ^ operator when calculating an index from the end of a collection |
false |
Prefer not to use the ^ operator when calculating an index from the end of a collection |
|
Default option value | true |
// csharp_style_prefer_index_operator = true
string[] names = { "Archimedes", "Pythagoras", "Euclid" };
var index = names[^1];
// csharp_style_prefer_index_operator = false
string[] names = { "Archimedes", "Pythagoras", "Euclid" };
var index = names[names.Length - 1];
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 IDE0056
// The code that's violating the rule is on this line.
#pragma warning restore IDE0056
To disable the rule for a file, folder, or project, set its severity to none
in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.IDE0056.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.