Code Syntax Style: Implicit/Explicit Typing
Using implicitly typed local variables (also known as var
keyword) introduced in C# 3.0 has become quite popular as it improves readability in many scenarios. By default, ReSharper also encourages using of var
keyword, but preferences of its usage are flexibly configurable — for example, you can opt for using explicit types in specific cases or everywhere and Rider will help you enforce your preferences.
Enforcing preferences of using 'var' keyword
Rider checks all local variables for compliance with your preferences and if they do not comply, Rider highlights such declarations and suggests the corresponding quick-fix or fix in scope.
By default, Rider's preferences say that 'var' keyword is preferred:
If you change your preference, Rider will help you to use explicit types:
Another option to enforce preferences of 'var' keyword usage in a bulk mode is code cleanup. You can either run code cleanup with the default profile Default: Full Cleanup or run the cleanup with a custom profile solely targeted at your specific task as described below.
To apply preferences of using 'var' keyword with custom Code Cleanup profile
- Press Ctrl+Alt+S, or alternatively choose on Windows and Linux or on macOS.
- Go to the Code Cleanup settings page: .
- Create a new profile as described in the Code Cleanup section. In the Selected profile settings section for the new profile, tick the Enforce 'var' keyword usage settings check box. Optionally, you can enable other code cleanup tasks in this profile.
- Click Save to apply the modifications and let Rider choose where to save them, or save the modifications to a specific settings layer using the Save To drop-down list. For more information, see layer-based settings.
- Select the scope where you want to enforce your preferences:
- Choose Code | Code Cleanup in the main menu.
- In the Code Cleanup dialog that opens, select the newly created profile.
- Click OK. Rider will enforce your preferences in the selected scope.
Configuring preferences of using 'var' keyword
Your 'var' keyword usage preferences are saved using the mechanism of layer-based settings. Among other things, this mechanism allows you to maintain different preferences for different solutions as well as to keep these preferences under a VCS and automatically share them with your team members.
To configure preferences of using 'var' keyword
- Go to the page of Rider settings (Ctrl+Alt+S), and then select the Code Style tab.
- Modify settings in the 'var' usage in declarations category according to your coding practices/standards. You can set different preferences of using 'var' or explicit type for different types:
- For built-in types - applies to C# built-in types.
- For simple types - applies to types without generic parameters.
- Elsewhere - applies to generic types.
- The selectors in the right column allow you to set severity levels of code inspections detecting code that differs from your preferences.
- Click Save to apply the modifications and let Rider choose where to save them, or save the modifications to a specific settings layer using the Save To drop-down list. For more information, see layer-based settings.
See Also
Procedures:
- Naming Style
- Managing and Applying Code Formatting Rules
- File and Type Layout
- File Header Style
- Code Syntax Style: Namespace Imports
- Code Syntax Style: Implicit/Explicit Typing
- Using Auto-Properties
- Making Fields Readonly
- Code Syntax Style: Multiple Attributes
- Code Syntax Style: Modifiers
- Code Syntax Style: Optional Member Qualifiers
- Reformatting XML Doc Comments
- Removing Code Redundancies