Introduce a local variable in Visual Studio

This code generation applies to:

  • C#

  • Visual Basic

What: Lets you immediately generate a local variable to replace an existing expression.

When: You have code which could be easily reused later if it were in a local variable.

Why: You could copy and paste the code multiple times to use it in various locations, however it would be better to perform the operation once, store the result in a local variable, and use the local variable throughout.

How-to

  1. Highlight the expression that you want to assign to a new local variable.

    • C#:

      Highlighted code C#

    • Visual Basic:

      Highlighted code VB

  2. Next, do one of the following:

    • Keyboard
      • Press Ctrl+. to trigger the Quick Actions and Refactorings menu.
    • Mouse
      • Right-click and select the Quick Actions and Refactorings menu.
      • Click the screwdriver icon that appears in the left margin if the text cursor is already on the line with the highlighted expression.

    Introduce local preview

  3. Select Introduce local for (all occurrences) of 'expression' from the drop-down menu.

    Tip

    Use the Preview changes link at the bottom of the preview window to see all of the changes that will be made before making your selection.

    The local variable is created, with the type inferred from its usage. Give the new local variable a new name.

    • C#:

      Implement interface result C#

    • Visual Basic:

      Implement interface result VB

    Note

    You can use the ...all occurrences of... menu option to replace every instance of the selected expression, not just the one you have specifically highlighted.

See also