Dictionaries and HashTables

Sub DictionaryTest()

Dim d As New Dictionary(Of String, Integer)

StartTimer()

'first test: writing 10 ^ n values, increasing size of the array by 1 each time

Dim i As Integer

For i = 0 To (10 ^ RunSize) - 1

d.Add(TestCode(i), i)

Next

'work out how long this took

WriteTime = ElapsedTime

'store ten values for subsequent tests

StoreTenValues()

'sort the dictionary (get list of keys first)

Dim keys As List(Of String) = d.Keys.ToList

keys.Sort()

SortTime = ElapsedTime

'third test: find 10 "random" values by number

Dim s As String

For i = (10 ^ RunSize) - 1 To 0 Step -(10 ^ (RunSize - 1))

s = d.Keys(i)

Next

'report how long this took

Read1Time = ElapsedTime

'fourth test: find 10 "random" values by name

For i = 0 To 9

s = d.Item(TextValues(i))

Next

Read2Time = ElapsedTime

'write out results of test

AddRow("Dictionary")

End Sub

Sub TestHashTable()

Dim ht As New Hashtable

StartTimer()

'first test: writing 10 ^ n values, increasing size of the array by 1 each time

Dim i As Integer

For i = 0 To (10 ^ RunSize) - 1

ht(i) = TestCode(i)

Next

'work out how long this took

WriteTime = ElapsedTime

'store ten values for subsequent tests

StoreTenValues()

'hash tables don't support native sorting

SortTime = 0

'third test: find 10 "random" values by number

Dim s As String

For i = (10 ^ RunSize) - 1 To 0 Step -(10 ^ (RunSize - 1))

s = ht.Keys(i)

Next

'report how long this took

Read1Time = ElapsedTime

'fourth test: find 10 "random" values by name

For i = 0 To 9

s = ht(TextValues(i))

Next

Read2Time = ElapsedTime

'write out results of test

AddRow("Hash Table")

End Sub