Code Syntax Style: Implicit/Explicit Typing ('var' Keyword)

Select ReSharper | Options from the main menu or press Alt+R O.

Go to the cleanup profiles settings page: Code Editing | Code Cleanup | Profiles.

Create a new profile as described in the Create a new custom cleanup profile section. In the Selected profile settings section for the new profile, tick the Enforce 'var' keyword usage settings checkbox. Optionally, you can enable other code cleanup tasks in this profile.

Click Save in the Options dialog to apply the modifications and let ReSharper choose where to save them, or save the modifications to a specific settings layer by choosing this layer from the Save To selector. For more information, see manage and share resharper settings.

Select the scope where you want to enforce your preferences:

• Place the caret anywhere in the file to enforce your preferences to the file.

• Select one or more items in the Solution Explorer to enforce your preferences in the files under these nodes and their child items.

Do one of the following:

• Press Control+Alt+F or choose ReSharper | Edit | Cleanup Code… from the main menu .

• Right-click anywhere in the text editor or right-click the selection and choose Cleanup Code in the context menu.

In the Code Cleanup dialog that opens, select the newly created profile .

Click Run. ReSharper will enforce your preferences in the selected scope.

Select ReSharper | Options from the main menu or press Alt+R O.

Go to the cleanup profiles settings page: Code Editing | Code Cleanup | Profiles.

Select your custom Code Cleanup profile and click Set as default (the default profile is also used for silent cleanup).

Go to the Code Editing | Code Cleanup | General options page and select Automatically run cleanup when saving a file.

Optionally, you can restrict automatic cleanup to specific files by a file mask.

You can also select Only changed parts of file to make sure that cleanup is applied to the code affected by your changes, and the rest of the code in the file is not modified.

If you choose to clean up only the changed parts of files, you can fine-tune this behavior with the following options:

• Perform full cleanup if partial cleanup is not possible — depending on this option, ReSharper will either clean up the whole file or skip the file if it is not possible to restrict the cleanup to the modified parts of the file.

• Allow cleanup on save for shared files — use this option to enable or disable partial cleanup in files that are included in the solution several times, such as files from shared projects.

Click Save in the dialog to apply the modifications and let ReSharper choose where to save them, or save the modifications to a specific settings layer by choosing this layer from the Save To selector. For more information, see manage and share resharper settings.

The next time you finish editing and save the file (Ctrl+S) or all files (Ctrl+Shift+S) , ReSharper will clean up the affected files using the selected profile. If the default cleanup profile is not selected, ReSharper will prompt you to choose one of the profiles.

Go to the Code Editing | C# | Syntax Style page of ReSharper options Alt+R, O.

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 and deconstruction declarations.

For each of these preferences you can opt for using 'var', explicit type, or 'var' when evident.

If you have chosen Use 'var' when evident in the previous step, you can opt to apply Visual Studio logic to decide which cases should be considered evident.

To learn the differences between ReSharper and Visual Studio logic, refer to Use 'var' when evident: what is considered evident?.

By default, ReSharper will suggest joined notation for multiple var's in deconstruction declarations, for example var (x, y) = GetTuple();. You can select Prefer separate declarations for deconstructed variables to opt for separate notation, for example (var x, var y) = GetTuple();.

By default, ReSharper suggests using standalone _ for discards, for example (_, _) = (0, 1);. You can select Use 'var' keyword for discards to always use var with discards where appropriate thus making sure that there are no conflicts with variables in the scope that may be named _.

The Notify with selectors in the right column allow you to set severity levels of code inspections detecting code that differs from your preferences.

Click Save in the Options dialog to apply the modifications and let ReSharper choose where to save them, or save the modifications to a specific settings layer by choosing this layer from the Save To selector. For more information, see manage and share resharper settings.

Place the caret to a code issue highlighted by a ReSharper's inspection.

Press Alt+Enter or click the action indicator to the left of the caret to open the action list.

In the action list, go to Inspection "Use preferred 'var' style" | Configure code style and then select a desired preference:

Your change will be saved using the smart save logic.

If you need to save the modified style preference in a shared settings layer, click the Configure code style menu item or press Enter when it is selected. ReSharper will open the Code Editing | C# | Syntax Style page of ReSharper options where you can modify your preference as needed, click Save To and then choose the desired settings layer.