Android Question [solved]question on "Null"

[Maodge]

pls look at the following code

dim map1 as map
dim s as string
dim o as object

    map1.Initialize
    map1.Put("4","d")
    map1.Put("1","a")
    map1.Put("101","a")

s = map1.get(1) ' s = null
o = map1.Get(1) 'o = null

    If s<> Null Then
        Log("s is not null")
    Else
        Log("s is null")
    End If

    If o<> Null Then
        Log("o is not null")
    Else
        Log("o is null")
    End If

run the program, the log shows"
s is not null
o is null

so why first if s<> Null then... prgram judge (s<> Null) = True
and the second if o<> Null Then... prgram judge (o<> Null) = False ?
What leads to such result?
Thanks

 

[Erel]

"1" is not the same as 1.

The first key is a string and the second is an int.

 

[Maodge]

"1" is not the same as 1.

The first key is a string and the second is an int.

thanks.maybe i did not decribe question clear.
i want know why
first if s<> Null then... prgram judge (s<> Null) = True
and the second if o<> Null Then... prgram judge (o<> Null) = False
the different between s and o -- s is string type and o is object type.
Did type can effect the result of logic equals?

 

[Erel]

I recommend you to check whether the map contains the key with Map.ContainsKey. It is simpler than dealing with nulls.

The compiler will convert the Null object to "null" string when you assign Null to a string.