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Due to a new functionality we need another instance constructor in a class called C_Geo_Data. This class contains a constructor as following:

        Public Sub New(_coord_Y As Double, _coord_X As Double, ByVal _srid As Integer)
        '...
        End Sub

Now we need to add another constructor with following parameters:

        Public Sub New(_coord_Y As Double, _coord_X As Double, ByVal _coord_Z As Double)
        '...
        End Sub

Note the difference in data type for the third parameter. Now there is already a function in the class calling this constructor and for the third parameter a string is handed over to the constructor. Of course the compiler doesn't know which constructor to use and gives a compile error as following:

Overload resolution failed because no accessible 'New' can be called without a narrowing conversion:
'Public Sub New(_coord_Y As Double, _coord_X As Double, _coord_Z As Double)': Argument matching parameter '_coord_Z' narrows from 'String' to 'Double'.
'Public Sub New(_coord_Y As Double, _coord_X As Double, _srid As Integer)': Argument matching parameter '_srid' narrows from 'String' to 'Integer'.

I fixed the error by explicitly converting the string to an integer (CInt(string)) but i wondered if there is any way to tell the caller which constructor to use without converting the parameter beforehand:

maybe something like this:

Dim test As String ="4326"
New GeoPoint(y,x,_srid=test)
bautista
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    _"without converting the parameter beforehand"_ Actually, you should convert it to an Integer even if you only had one constructor. If you had `Option Strict` turned on (which you should absolutely do), the compiler wouldn't have allowed you to pass a string in place of an Integer or Double. See [What do Option Strict and Option Explicit do?](https://stackoverflow.com/q/2454552/8967612) for more information. – 41686d6564 stands w. Palestine Aug 24 '20 at 14:10
  • You dont need the spatial reference identifier when specifying the z coordinate? – Magnus Aug 24 '20 at 14:10
  • @Magnus No i dont need it, when converting the third parameter to a int before. – bautista Aug 25 '20 at 06:13

1 Answers1

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You've almost got the right answer. But you need a colon after the parameter name.

Dim test As String ="4326"
New GeoPoint(y,x,_srid:=test)
CB_Ron
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