B4J Question [B4X] CreateMap and Null values

LucaMs

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I found that CreateMap accepts Null values as well, like so:
B4X: 
MyMap = CreateMap("Value":Null)
but If I had something like:
B4X: 
MyMap = Create(Null)

Private Sub Create(Value As Map) As Map
    Return CreateMap("Value":Value)
End Sub
I would get an error: java.lang.RuntimeException: Object should first be initialized (Map) <--- Map Value, the parameter.

Obviously I got around this problem easily but I wonder if it is right for this to happen.
 
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LucaMs

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FrostCodes said:
Your Sub is accepting a Map value not an object so that's why it's crashing. Null is not a Map.
Click to expand...
That's not the problem, it's creating the Map that way.
You could have:
B4X: 
    MyMap = Create2(Null)
    Log(MyMap)'ignore

Private Sub Create2(Value As Map) As Map
    Return Value
End Sub
without getting errors.

Erel said:
Change the type of Value to Object.
Click to expand...
LucaMs said:
Obviously I got around this problem easily but I wonder if it is right for this to happen.
Click to expand...
 
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LucaMs

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Licensed User
Longtime User
Erel said:
Change the type of Value to Object.
Click to expand...
LucaMs said:
Obviously I got around this problem easily .
Click to expand...
Setting the parameter type to Object is not a good choice; the developer needs to know what kind of data to pass.

More correctly I check that the past Map is initialized depending on whether it is or not...
B4X: 
Private Sub Create(Value As Map) As Map
    If Value.IsInitialized Then
        Return CreateMap("Value":Value)
    Else
        Return CreateMap("Value":Null)
    End If
End Sub
 
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