Naming for Namespace, Class, and Variables - Page 2

subaru_sti · #11 (**permalink**) 07-08-2009, 12:13 AM

Good point... This is confusing.

So since I am dealing with GPS data, should I name the class GPS and the property Speed?

Stephen

jmcilhinney · #12 (**permalink**) 07-08-2009, 12:27 AM

That sounds reasonable. Given the situation though, does it even make sense to be able to set that property? Presumably you're calculating speed based on the last two locations and the time between them, so it really doesn't make sense for you to be setting that value from the outside. It's value should always be calculated from the inside. In that case it should be a ReadOnly property and have only a Get method.

subaru_sti · #13 (**permalink**) 07-08-2009, 12:30 AM

This value actually gets passed in by the GPS device so I do want to do some basic validation on it.

Thanks for all of your help!

Stephen

subaru_sti · #14 (**permalink**) 07-08-2009, 1:08 AM

For Speed, it doesn't make sense to have MetersPerSecond as the property because you could be passing KM/H or MPH, etc. Just jumping back to Heading... I am adding another function that determines your direction (north, south, east, and west) based on a degree value from 0 to 360. Would it be wrong to change the property for the Heading class from "Direction" to "Degree"? I know degree is the type but I am going to be passing the "degree" value to the direction function to determine N, S, E, or W as well.

It is just not making sense to me...

Stephen

jmcilhinney · #15 (**permalink**) 07-08-2009, 1:18 AM

You shouldn't be naming properties after units. The property returns a value measured in those units. It doesn't return the unit. Would not Angle be a suitable name for a value that's measured in degrees?

I'd also be inclined to use a ReadOnly property to expose the N, S, E & W values and calculate them on the fly. You should also define an enumeration for the values:

Code:

Public Enum Direction
    North
    South
    East
    West
End Enum

Code:

Private _angle As Double

Public Property Angle() As Double
    Get
        Return Me._angle
    End Get
    Set(ByVal value As Double)
        Me._angle = value Mod 360
    End Set
End Property

Public ReadOnly Property Direction() As Direction
    Get
        Dim value As Direction

        Select Case Me.Angle
            Case Is < 45
                value = Direction.North
            Case Is < 135
                value = Direction.East
            Case Is < 225
                value = Direction.South
            Case Is < 315
                value = Direction.West
            Case Else
                value = Direction.North
        End Select

        Return value
    End Get
End Property

subaru_sti · #16 (**permalink**) 07-08-2009, 1:30 AM

Okay, I think I got it now.

Stephen

jmcilhinney · #17 (**permalink**) 07-08-2009, 1:32 AM

Actually, given that you're moving at a particular angle I would think Heading or Bearing would be the most appropriate property name. I know you mentioned Heading before but I'm not going to read back to find out where.

subaru_sti · #18 (**permalink**) 07-08-2009, 1:33 AM

I am using Heading as the class name.

Stephen

jmcilhinney · #19 (**permalink**) 07-08-2009, 2:22 AM

In that case Bearing might be the best name. Also, such a type has the look of a structure to me, rather than a class, much like Point and Size.

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