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vb.netdictionarykeyvaluepair

Get Dictionary item as KeyValuePair

For me it seems to be obvious that a dictionary might have a method for getting it's item by Key. Either I am blind, or... However, I have following situation:

A need a Dictionary(Of Integer, k/v). I have the k/v's already in a Dictionary and I'd like to add them to my new one by Key, such as:

'Dict1 has {("Key1", 123), ("Key2", 345)}
Dim dict2 As New Dictionary (Of Integer, KeyValuePair(Of String, Double))
dict2.Add(0,***dict1.GetItem("Key1")***)

Sure I could write an extension, and probably I'll have to, but is it only me missing this function? If there was a built in way I've overseen, please point me there!

Thanks in advance,

Daniel

EDIT:

dict1 = {(0, "apples"), (1, "oranges"), (2, "bananas")}
dict2 = {("oranges", 456), ("apples", 123), ("bananas", 789)}

the new dictionary is a sorted dict2 by dict1:

dictnew = {("apples", 123), ("oranges", 456), ("bananas", 789)}

So my approach was:

dicttemp = {(0, ("apples", 123)), (1, ("oranges", 456)), (2, ("bananas", 789))}'. `dicttemp` is a `SortedDictionary`.

Next I get the values of dicttemp and transform them into a Dictionary.

Solution

  • You're looking for dictionary's indexer.

    Dim a As Double = dict1("Key1")

    In some comment, OP said:

    I need the whole item as k/v and add the item of dict1 to dict2!!!

    Since a dictionary implements IEnumerable(Of T) where T is KeyValuePair(Of TKey, TValue), you can use Single(...) LINQ extension method to find out a key-value pair by key:

    Dim pair As KeyValuePair(Of String, Double) = dict1.Single(Function(item) item.Key = "key")

    Since dictionary's Add method has an overload to give a key-value pair as argument, I believe that adding dict1 key-value pair to dict2 is just about calling Add in the second dictionary providing the obtained key-value pair from first dictionary:

    dict2.Add(pair);