Conditional to Switch/Switch to Conditional

• Dec 13, 2018
• 2 minutes to read

Purpose

Converts nested if-else blocks into a single switch (Select) statement or vice versa. We recommend using the switch statement when the selector is discrete. If you need to check continuous ranges, use the if-else cascade.

Conditional to Switch and Switch to Conditional refactorings also support pattern matching.

Availability

• The Conditional to Switch refactoring is available when the caret is in an if statement that has a corresponding else block.
• The Switch to Conditional refactoring is available when the caret is in a switch (Select) statement.

Usage

1. Place the caret on the if statement that has a corresponding else block.

   NOTE

   The blinking cursor shows the caret's position at which the Refactoring is available.

   C#

   public static int GetTotal(IEnumerable<object> values) {
       var sum = 0;
   
       foreach (var item in values) {
           │if (item is int val)
               sum += val;
           else if (item is IEnumerable<object> sublist)
               sum += GetTotal(sublist);              
       }
       return sum;
   }
   

   VB.NET

   │If i = 1 Then
      i += 1
   Else
      If i = 2 Then
          i -= 1
      Else
          i = 0
      End If
   End If
   

2. Use the Ctrl + . or Ctrl + ~ shortcut to invoke the Code Actions Menu.
3. Select Conditional to Switch from the menu (Switch to Conditional if you are converting the switch (Select) statement into nested conditionals).

After execution, the Refactoring converts the conditionals into a single switch (Select) statement or vice versa.

C#

public static int GetTotal(IEnumerable<object> values) {
    var sum = 0;         

    foreach (var item in values) {
        switch (item) {
            case int val:
            sum += val;
            break;
            case IEnumerable<object> sublist:
            sum += GetTotal(sublist);
            break;
        }
    }
    return sum;
}

VB.NET

Select Case i
    Case 1
        i += 1
    Case 2
        i -= 1
    Case Else
        i = 0
End Select