Convert Dictionary, List

A VB.NET Dictionary can be converted to a List. It can be represented as a List of KeyValuePairs. The ToList Function is useful here.

In converting Dictionaries and Lists, we have to understand that we may need to have KeyValuePairs. We demonstrate this conversion in the VB.NET language.

Example

We are acting on a Dictionary of String keys and Integer values, but these types can be changed. The Dictionary is a generic type, so it can be used with many key and value types.

Module Module1
    Sub Main()
        ' Step 1: create example dictionary.
        Dim dict As Dictionary(Of String, Integer) = New Dictionary(Of String, Integer)()
        dict("cat") = 1
        dict("dog") = 2
        dict("mouse") = 3
        dict("palomino") = 4

        ' Step 2: call ToList on it (use KeyValuePair list).
        Dim list As List(Of KeyValuePair(Of String, Integer)) = dict.ToList

        ' Step 3: we can loop over each KeyValuePair.
        For Each pair As KeyValuePair(Of String, Integer) In list
            Console.WriteLine(pair.Key)
            Console.Write("  ")
            Console.WriteLine(pair.Value)
        Next
    End Sub
End Module
cat
  1
dog
  2
mouse
  3
palomino
  4

Discussion

Why would a programmer want to convert a Dictionary into a List? Looping over every element in a List is much faster than looping over all the pairs in a Dictionary.

Here we converted a Dictionary into a List. A List of KeyValuePairs can always represent the data inside a Dictionary. The main difference between is performance.