Android Question Code smells

[RB Smissaert]

Had a look at Erel's posting Code smells:

[B4X] "Code Smells" - common mistakes and other tips

"Code smells" are common patterns that can indicate that there is a problem in the code. A problem doesn't mean that the code doesn't work, it might be that it will be difficult to maintain it or that there are more elegant ways to implement the same thing. Remember that not everything is clear...

www.b4x.com

and looked at GetKeyAt and GetValue at of Map.

I take it that if we are only interested in the key or value at one particular index we have to do something like this (although it looks inefficient):

Sub GetMapKeyAt(oMap As Map, iIndex As Int) As Object

Dim i As Int

For Each oKey As Object In oMap.Keys
If i = iIndex Then
Return oKey
End If
i = i + 1
Next

Return Null

End Sub
Sub GetMapValueAt(oMap As Map, iIndex As Int) As Object

Dim i As Int

For Each oValue As Object In oMap.Values
If i = iIndex Then
Return oValue
End If
i = i + 1
Next

Return Null

End Sub
[CODE/]


RBS

 

[tchart]

Yeah I was a bit surprised that Map.GetKeyAt / GetValueAt are to be deprecated.

I use these often, especially for returning chart data (x,y) from the database as a map.

 

[LucaMs]

I think that the only reason is:

They are not cross platform

Because (again an Erel' statement):
Note that in most implementations of maps the order is not preserved. In most use cases the order is not important.
The order in B4A and B4J maps is preserved. This is not the case in B4i.

Also, given that:

B4XOrderedMap - Similar to a Map with two advantages:

1. The order of items is preserved. This is the case with regular Maps in B4A and B4J as well, however not the case with B4i regular Maps.

2. You can sort the items based on the keys.

and that it is part of a b4xlib (which means that you have the source code), I think it is a good "practice" to use that library.

Anyway, you can still use those properties (when working with B4A or B4J), of course, "deprecated" does not mean "prohibited".

 

[Erel]

Use B4XOrderedMap if you need to access the items based on their index.
The standard Map is not built for such access and it actually iterates over the items internally.