Promote to Parameter (optional)

• Apr 17, 2018
• 2 minutes to read

Removes all references to the local declaration from the method, replacing it with an optional parameter.

Promote to Parameter (optional) is a cascading refactoring. That is, the refactoring affects all method calls and method declarations in interfaces, base and descendant classes.

Purpose

This refactoring makes a method much more flexible. Technically, it allows you to initialize its local variable in the calling statement. This extends the method’s application area.

Availability

Available from the context menu or via shortcuts:

• when the caret is on a local variable name within the variable declaration statement.

Example

C#

public string TestMethod()
{
    int │myVar = 15;
    return String.Format("MyField value is {0}", myVar);
}
private void CallTestMethod()
{
    string str = TestMethod();
}

VB.NET

Private Function TestMethod() As String
    Dim │myInt As Integer = 15
    Return String.Format("MyField value is {0}", myInt)
End Function
Private Sub CallTestMethod()
    Dim str As String = TestMethod()
End Sub

Result:

C#

public string TestMethod(int myVar = 15)
{
    return String.Format("MyField value is {0}", myVar);
}
private void CallTestMethod()
{
    string str = TestMethod(15);
}

VB.NET

Private Function TestMethod(Optional ByVal myInt As Integer = 15) As String
    Return String.Format("MyField value is {0}", myInt)
End Function
Private Sub CallTestMethod()
    Dim str As String = TestMethod(15)
End Sub

Screenshot