[기타] [VB.NET] Sort Examples: Arrays and Lists - Dot Net Perls
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1. VB.NET program that uses Array.Sort on strings
Module Module1
Sub Main()
' Create an array of String() with 3 elements.
Dim vegs As String() = New String() {"turnip",
"onion",
"corn"}
' Use the System.Array.Sort shared method.
System.Array.Sort(vegs)
' Loop through the results and print them with Console.WriteLine.
For Each value As String In vegs
Console.WriteLine(value)
Next
End Sub
End Module
corn
onion
turnip
2. VB.NET program that uses Sort and Reverse methods
Module Module1
Sub Main()
' Create a String array with 5 elements.
Dim array As String() = New String() {"X", _
"B", _
"A", _
"Z", _
"C"}
' Use the System.Array.Sort shared method.
System.Array.Sort(Of String)(array)
' Invoke the Reverse method after sorting.
System.Array.Reverse(array)
' Loop through the results.
Dim value As String
For Each value In array
Console.WriteLine(value)
Next
End Sub
End Module
Z
X
C
B
A
3. VB.NET program that uses descending sort
Module Module1
Function DescendingComparison(ByVal valueA As String,
ByVal valueB As String) As Integer
' Invert the order of the comparison to sort in descending order.
Return valueB.CompareTo(valueA)
End Function
Sub Main()
Dim letters As String() = {"X",
"B",
"A",
"Z",
"C"}
' Use custom DescendingComparison to sort in reverse.
Array.Sort(Of String)(letters, New Comparison(Of String)(AddressOf DescendingComparison))
' Display results.
For Each value As String In letters
Console.WriteLine("DESCENDING: {0}", value)
Next
End Sub
End Module
DESCENDING: Z
DESCENDING: X
DESCENDING: C
DESCENDING: B
DESCENDING: A
4. VB.NET program that uses List Sort method
Module Module1
Sub Main()
' Create a List of Strings and add 4 Strings to it.
Dim list As New List(Of String)
list.Add("chair")
list.Add("table")
list.Add("desk")
list.Add("couch")
' Use Sort method.
list.Sort()
' Loop through the results and display them.
Dim value As String
For Each value In list
Console.WriteLine(value)
Next
End Sub
End Module
chair
couch
desk
table
5. VB.NET program that uses lambda, sorts List
Module Module1
Sub Main()
Dim numbers = New List(Of Integer)({20, 30, 40})
' Use lambda to sort list in descending order.
numbers.Sort(Function(valueA, valueB) valueB.CompareTo(valueA))
For Each number As Integer In numbers
Console.WriteLine("LAMBDA SORTED NUMBER: {0}", number)
Next
End Sub
End Module
LAMBDA SORTED NUMBER: 40
LAMBDA SORTED NUMBER: 30
LAMBDA SORTED NUMBER: 20
6. VB.NET program that uses Copy, Sort
Module Module1
Sub Main()
Dim names() As String = {"Zach", "Andrew", "David"}
' Create a copy of names array and sort it.
Dim namesCopy(2) As String
Array.Copy(names, namesCopy, 3)
Array.Sort(namesCopy)
' Display arrays.
Console.WriteLine(String.Join(",", names))
Console.WriteLine(String.Join(",", namesCopy))
End Sub
End Module
Zach,Andrew,David
Andrew,David,Zach
7. VB.NET program that sorts on 2 Tuple values
Module Module1
Function GetData() As List(Of Tuple(Of Integer, Integer))
Dim result As New List(Of Tuple(Of Integer, Integer))
result.Add(New Tuple(Of Integer, Integer)(100, 1))
result.Add(New Tuple(Of Integer, Integer)(100, 2))
result.Add(New Tuple(Of Integer, Integer)(10, 2))
result.Add(New Tuple(Of Integer, Integer)(10, 1))
Return result
End Function
Function ComparisonTwoTuples(ByVal tupleA As Tuple(Of Integer, Integer),
ByVal tupleB As Tuple(Of Integer, Integer)) As Integer
' Compare the first Item of each tuple in ascending order.
Dim part1 As Integer = tupleA.Item1
Dim part2 As Integer = tupleB.Item1
Dim compareResult As Integer = part1.CompareTo(part2)
' If not equal, return the comparison result.
If compareResult <> 0 Then
Return compareResult
End If
' Compare the second item of each tuple in descending order.
Return tupleB.Item2.CompareTo(tupleA.Item2)
End Function
Sub Main()
Dim data As List(Of Tuple(Of Integer, Integer)) = GetData()
data.Sort(New Comparison(Of Tuple(Of Integer, Integer))(AddressOf ComparisonTwoTuples))
For Each value In data
Console.WriteLine("SORTED ON 2 VALUES: {0}", value)
Next
End Sub
End Module
SORTED ON 2 VALUES: (10, 2)
SORTED ON 2 VALUES: (10, 1)
SORTED ON 2 VALUES: (100, 2)
SORTED ON 2 VALUES: (100, 1)
8. VB.NET program that benchmarks List, SortedSet
Module Module1
Sub Main()
Dim m As Integer = 100000
Dim s1 As Stopwatch = Stopwatch.StartNew
' Version 1: add 3 strings to List, then Sort it.
For i As Integer = 0 To m - 1
Dim list = New List(Of String)
list.Add("zebra")
list.Add("20")
list.Add("bird")
list.Sort()
If list.Count <> 3 Then
Return
End If
Next
s1.Stop()
Dim s2 As Stopwatch = Stopwatch.StartNew
' Version 2: add 3 strings to SortedSet.
For i As Integer = 0 To m - 1
Dim sorted = New SortedSet(Of String)
sorted.Add("zebra")
sorted.Add("20")
sorted.Add("bird")
If sorted.Count <> 3 Then
Return
End If
Next
s2.Stop()
Dim u As Integer = 1000000
Console.WriteLine(((s1.Elapsed.TotalMilliseconds * u) / m).ToString("0.00 ns"))
Console.WriteLine(((s2.Elapsed.TotalMilliseconds * u) / m).ToString("0.00 ns"))
End Sub
End Module
405.52 ns List, Sort
357.17 ns SortedSet
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