Two dim array by Object, problem writing new value into x,y position

[PeterBunde]

Fellow sufferers

I am using Object class to create a two-dimensional array. See code below.

Sometimes, I ned to overwrite the valie at x,y. Now, if that value has already been set, there is an error. But just asking if it is empty, apparently sets the value, but to "".

What is the right code to write a value into the x,y position - with or without it being previously defined?

Sub Test()
Dim inhabitants_in As Object
Set inhabitants_in = CreateObject("Scripting.Dictionary")
' add countries
inhabitants_in.Add "Norway", CreateObject("Scripting.Dictionary")
inhabitants_in.Add "France", CreateObject("Scripting.Dictionary")
inhabitants_in.Add "Italy", CreateObject("Scripting.Dictionary")
' add cities and number of inhabitants
inhabitants_in("Norway").Add "Oslo", 9
inhabitants_in("France").Add "Paris", 200
inhabitants_in("Italy").Add "Roma", 300
inhabitants_in("Italy").Add "Milano", 400
inhabitants_in("Italy").Add "Firenze", 500
inhabitants_in("Italy").Add "Venezia", 600
inhabitants_in("Norway")("Oslo") = 800
MsgBox (inhabitants_in("Norway")("Hardanger"))
inhabitants_in("Norway").Add "Hardanger", 111600  '<<< This line fails
MsgBox (inhabitants_in("Norway")("Hadanger"))
' Show values
MsgBox _
    inhabitants_in("Italy")("Venezia") & vbNewLine & _
    inhabitants_in("France")("Paris") & vbNewLine & _
    inhabitants_in("Norway")("Oslo")
    
End Sub

 

[Eric W]

Your problem is the MsgBox line above it. That tries to print the value (item) of inhabitants_in("Norway")("Hardanger"), which doesn't exist at that time, but trying to reference it causes it to be created. So when you try to add it on the next line, it says you have a duplicate key.

You can actually use this behavior to your advantage. Instead of using .Add, you can do this:

inhabitants_in("Norway")("Hardanger") = 111600

If that key exists, it will update it. If that key does not exist, it will create it and update the item.

If you just want to see if the key exists, without creating it, use .Exists instead.

(It also appears you misspelled Hardanger in the next line.)

Hope this helps.