I have a list of date values
10/06/2017, 4/20/12, 7/13/12, 08.02.12, 04.05.13, 11.27.12
that needs to be sorted into correct chronological order.
The format from the original data entry was not controlled and therefore is variable. Date seperators, thus far, have shown to be '.' and '/'. The number of digits in each date segment are not consistent.
This list represents a single column of data in a table. The data is read from varying sources and can be put into any structure that will facilitate the sort. The date must sort the entire table.
The data must remain as originally entered so I cannot simply convert the data and be done with it.
Here's a function and overload which will work with either a string as you provided, or a list of strings:
Private Function getSortedDates(input As String) As IEnumerable(Of DateTime)
Return getSortedDates(input.Split({","c}, StringSplitOptions.RemoveEmptyEntries))
End Function
Private Function getSortedDates(input As IEnumerable(Of String)) As IEnumerable(Of DateTime)
Return input.
Select(Function(s As String) DateTime.Parse(s.Replace(".", "/"))).
OrderBy(Function(d) d)
End Function
Usage:
Sub Main()
' as a string
Dim input1 = "10/06/2017, 4/20/12, 7/13/12, 08.02.12, 04.05.13, 11.27.12"
Dim output1 = getSortedDates(input1)
' as an array
Dim input2 = {"10/06/2017", "4/20/12", "7/13/12", "08.02.12", "04.05.13", "11.27.12"}
Dim output2 = getSortedDates(input2)
' output1 and output2 have the same sorted dates.
End Sub
You can build a custom Comparer that can be used in sorting
Module Module1
Sub Main()
Dim dates() As String = {"10/06/2017", "4/20/12", "7/13/12", "08.02.12", "04.05.13", "11.27.12"}
Array.Sort(dates, New StringDateSorter)
For Each d In dates
Console.WriteLine(d)
Next
End Sub
End Module
Class StringDateSorter
Implements IComparer(Of String)
Public Function Compare(x As String, y As String) As Integer Implements IComparer(Of String).Compare
Dim d1 = Date.Parse(x)
Dim d2 = Date.Parse(y)
Return Date.Compare(d1, d2)
End Function
End Class
Related
In order to display big numbers I need to be able to retrieve the powers of two in decimal string format. The following code is the best I could do, is there a faster way?
Public NotInheritable Class TwoPowerOf
Private DecimalString As String = ""
Public Sub New(ByVal MyInteger As Integer)
If MyInteger > -256 And MyInteger < 1024 Then
Me.DecimalString = GetTwoPowerOf(MyInteger)
End If
End Sub
Public Overrides Function ToString() As String
Return Me.DecimalString
End Function
Protected Function GetTwoPowerOf(ByVal MyInteger As Integer) As String
Dim result As String = ""
Dim d As New Dictionary(Of Integer, String)
'...
d.Add(2, "4")
d.Add(1, "2")
d.Add(0, "1")
d.Add(-1, "0.5")
d.Add(-2, "0.25")
d.Add(-3, "0.125")
d.Add(-4, "0.0625")
d.Add(-5, "0.03125")
d.Add(-6, "0.015625")
d.Add(-7, "0.0078125")
d.Add(-8, "0.00390625")
' ...
result = d.Item(MyInteger)
Return result
End Function
End Class
And retreiving is something like this:
Sub whatever()
Dim MyInteger as Integer
Dim MyDecimalString as String = New TwoPowerOf(MyInteger).ToString
Console.WriteLine(MyDecimalString)
End Sub
Or, is there a way to convert big binary numbers into decimals without using the powers of two?
I'm using vb.net. I am doing some checking and scrubbing of my data when i get it from the database. I'm using an overload but it doesn't seem to be working for decimal numbers. Decimal numbers get treated as integers.
Public Class CheckData
Public Shared Function Check(row As DataRow, columnName As String, pDefaultValue As Decimal) As Decimal
Dim x As Object = ReplaceDBNullAndColumnExists(row, columnName)
Dim y As Decimal = CDec(Dempsey.fnIsNull.IsNull(x, pDefaultValue))
Return y
End Function
Public Shared Function Check(row As DataRow, columnName As String, pDefaultValue As DateTime) As DateTime
Dim x As Object = ReplaceDBNullAndColumnExists(row, columnName)
Dim y As DateTime = Dempsey.fnIsNull.IsNull(x, pDefaultValue)
Return y
End Function
Public Shared Function Check(row As DataRow, columnName As String, pDefaultValue As Integer) As Integer
Dim x As Object = ReplaceDBNullAndColumnExists(row, columnName)
Dim y As Integer = Dempsey.fnIsNull.IsNull(x, pDefaultValue)
Return y
End Function
Public Shared Function Check(row As DataRow, columnName As String, pDefaultValue As String) As String
Dim x As Object = ReplaceDBNullAndColumnExists(row, columnName)
Dim y As String = Dempsey.fnIsNull.IsNull(x, pDefaultValue)
Return y
End Function
Public Shared Function Check(row As DataRow, columnName As String, pDefaultValue As Boolean) As Boolean
Dim x As Object = ReplaceDBNullAndColumnExists(row, columnName)
Dim y As Boolean = Dempsey.fnIsNull.IsNull(x, pDefaultValue)
Return y
End Function
So if i pass in some data and the type is a string, integer, boolean or datetime it goes to the propert function. if i pass in a decimal it goes to integer. If i set a breakpoint on the public shared function check that is a integer function and do a
row.Table.Columns(columnName).DataType.Name
I get back - "Decimal" (doing this in the immediate window)
So my question is what have i done wrong that it doesn't take it to the decimal overload and return a decimal value. By the way, the actual data value is 37.50.
Thanks
shannon
I use this to populate list.
Public Function populate(mDs As DataSet) As List(Of SR_SalaryRange_Current)
Dim rows As DataRowCollection
Dim drow As DataRow
Dim oSR_SalaryRange_Current As SR_SalaryRange_Current
Dim oSR_SalaryRange_Currents As List(Of SR_SalaryRange_Current) = New List(Of SR_SalaryRange_Current)
Dim dt As New DataTable
Try
dt = mDs.Tables("SR_SalaryRange_Currents")
rows = dt.Rows
For Each drow In rows
oSR_SalaryRange_Current = New SR_SalaryRange_Current
With oSR_SalaryRange_Current
.tblSR_SalaryRange_CurrentID = SitePlumbing.CheckData.Check(drow, "intTblSR_SalaryRange_CurrentID", 0)
.EffectiveDate = SitePlumbing.CheckData.Check(drow, "dtmEffectiveDate", CDate("1/1/1900"))
.WorkWeekHours = SitePlumbing.CheckData.Check(drow, "decWorkWeekHours", 0)
End With
oSR_SalaryRange_Currents.Add(oSR_SalaryRange_Current)
Next
Catch ex As Exception
ErrorMsg = "Populate Error:" & ex.InnerException.ToString
Return oSR_SalaryRange_Currents
End Try
Return oSR_SalaryRange_Currents
End Function
from there it goes into the checkdata that i mentioned before. In the code above it correctly goes to an integer and a datetime when hitting the overload, just isn't doing it for the decimal.
A decimal is implicitly covertable into an integer so the compiler is confused if you have OPTION STRICT set to off. You have two options:
1) Set OPTION STRICT to ON. Then the compiler will not convert implicitly.
2) Pass in a decimal literal like this: 10D (i.e. there is a D on the end telling the compiler it is a decimal).
For example:
'Sub Routine 1
public sub Test(ByVal d as decimal)
end sub
'Sub Routine 2
public sub Test(ByVal i as integer)
end sub
//Client
dim d1 as decimal={Number}D 'where {number} is replaced with a number
dim d2 as decimal={Number} 'where {number} is replaced with a number
Test(d1) 'this will always go to Sub Routine 1 regardless of whether OPTION strict is ON or OFF
Test(d2) 'this will go to Sub Routine 1 if option strict is ON. If it is OFF, then it may go to Sub Routine 2 depending on the size of the number.
I was given a way to work with this by Viorel on another forum. He suggested I do
Check(drow, "decWorkWeekHours", 0#)
and that did indeed work. When i asked what it does, this was his response.
With ‘#’, the constant ‘0#’ becomes a decimal one. Then VB.NET chooses the definition of Check that takes a Decimal parameter, since it is more suitable comparing with other candidates.
You can also write ‘0d’ [https://learn.microsoft.com/en-us/dotnet/visual-basic/programming-guide/language-features/data-types/type-characters].
hope that will help someone else down the road.
Thanks
shannon
I need to create a 2D dictionary/keyvalue pair.
I tried something like this.
Dim TwoDimData As New Dictionary(Of String, Dictionary(Of String, String))
'Create an empty table
For Each aid In AIDList '(contains 15000 elements)
TwoDimData.Add(aid, New Dictionary(Of String, String))
For Each bid In BIDList 'contains 30 elements
TwoDimData.Item(aid).Add(bid, "")
Next
Next
'Later populate values.
[some code here to populate the table]
'Now access the value
'The idea is to access the info as given below (access by row name & col name)
Msgbox TwoDimData.Item("A004").Item("B005") ' should give the value of 2
Msgbox TwoDimData.Item("A008").Item("B002") ' should return empty string. No error
Issue:
The issue is in Creating the empty table. It takes 70 seconds to create the TwoDimData table with empty values. Everything else seems to be fine. Is there any way to improve the performance - may be instead of using Dictionary?
I suggest you try Dictionary(Of Tuple(Of String, String), String) instead. That is, the keys are pairs of strings (Tuple(Of String, String)) and the values are strings. That would appear to correspond nicely to the diagram in your question.
Dim matrix As New Dictionary(Of Tuple(Of String, String), String)
' Add a value to the matrix:
matrix.Add(Tuple.Create("A003", "B004"), "3")
' Retrieve a value from the matrix:
Dim valueAtA003B004 = matrix(Tuple.Create("A003", "B004"))
Of course you can define your own key type (representing a combination of two strings) if Tuple(Of String, String) seems too generic for your taste.
Alternatively, you could also just use (possibly jagged) 2D arrays, but that would potentially waste a lot of space if your data is sparse (i.e. if there are many empty cells in that 2D matrix); and you'd be forced to use numeric indices instead of strings.
P.S.: Actually, consider changing the dictionary value type from String to Integer; your example matrix suggests that it contains only integer numbers, so it might not make sense to store them as strings.
P.P.S.: Do not add values for the "empty" cells to the dictionary. That would be very wasteful. Instead, instead of simply retrieving a value from the dictionary, you check whether the dictionary contains the key:
Dim valueA As String = "" ' the default value
If matrix.TryGetValue(Tuple.Create("A007", "B002"), valueA) Then
' the given key was present, and the associated value has been retrieved
…
End If
I would think that a simple structure would suffice for this?
Public Structure My2DItem
Public Row As Integer
Public Col As Integer
Public Value As String
End Structure
Public My2DArray As Generic.List(Of My2DItem) = Nothing
Public Size As Integer
Public MaxRows As Integer
Public MaxCols As Integer
'
Sub Initialise2DArray()
'
Dim CountX As Integer
Dim CountY As Integer
Dim Item As My2DItem
'
'initialise
MaxRows = 15000
MaxCols = 30
Size = MaxRows * MaxCols
My2DArray = New Generic.List(Of My2DItem)
'
'Create an empty table
For CountY = 1 To 15000
For CountX = 1 To 30
Item = New My2DItem
Item.Row = CountY
Item.Col = CountX
Item.Value = "0"
My2DArray.Add(Item)
Item = Nothing
Next
Next
'
End Sub
And to read the data out of the array,
Function GetValue(Y As Integer, X As Integer) As String
'
Dim counter As Integer
'
GetValue = "Error!"
If My2DArray.Count > 0 Then
For counter = 0 To My2DArray.Count - 1
If My2DArray(counter).Row = Y Then
If My2DArray(counter).Col = X Then
GetValue = My2DArray(counter).Value
Exit Function
End If
End If
Next
End If
'
End Function
And to read your sample cell A004 B005
MyStringValue = GetValue(4,5)
I would suggest creating a class that has properties for the AID and BID and use this as the basis for the values you want to store
Public Class AIdBId
Public Property AId As Integer
Public Property BId As Integer
Public Sub New(aId As Integer, bId As Integer)
Me.AId = aid
Me.BId = bid
End Sub
End Class
Note that I have used integers for everything because it seems that is all you need and it is more efficient that using a string
Then you can add values where they are non-zero:
'define your dictionary
Dim valueMatrix As New Dictionary(Of AIdBId, Integer)
'add your values
valueMatrix.Add(New AIdBId(1, 1), 1)
valueMatrix.Add(New AIdBId(2, 3), 1)
valueMatrix.Add(New AIdBId(4, 3), 3)
valueMatrix.Add(New AIdBId(5, 8), 8)
'check if a value exixts
Dim valueExixsts As Boolean = valueMatrix.ContainsKey(New AIdBId(9, 9))
'get a value
Dim i As Integer = valueMatrix(New AIdBId(4, 3))
So you can now combine these two to return the value if there is one or zero if not:
Private Function GetValue(valuematrix As Dictionary(Of AIdBId, Integer), aId As Integer, bId As Integer) As Integer
Dim xRef As New AIdBId(aId, bId)
If valuematrix.ContainsKey(xRef) Then
Return valuematrix(xRef)
Else
Return 0
End If
End Function
I got the following strings arrays
a.csv
a-1.csv
a-2.csv
a-3.csv
ab.csv
ab-1.csv
ab-2.csv
cccc.csv
cccc-1.csv
d.csv
In this strings arrays, it stores a series of test data, the naming conversion for each test data is as follows,
'unit name'+'-'+('suffix in single digit number')+'.csv'
The length of the unit name could be any length, but the suffix can only be single-digit number (1-9). For example for unit a, it undergoes 4 test in total, which are a.csv, a-1.csv, a-2.csv and a-3.csv. But because all of the first three test fails the specs, therefore only the last test data will be retrieved for analysis, which is a-3.csv.
So, for the final output, I only need those data which have the largest suffix for each unit, which gives me the output string array:
a-3.csv
ab-2.csv
cccc-1.csv
d.csv
How should I choose the correct files from the input string array according to the rules to get those test data only got the largest suffix.
Private Function Suffix(ByVal s As String) As String
s = IO.Path.GetFileNameWithoutExtension(s)
Dim pos = s.LastIndexOf("-"c)
Return If(pos = -1, s, s.Substring(0, pos))
End Function
Private Function Value(ByVal s As String) As Integer
s = IO.Path.GetFileNameWithoutExtension(s)
Dim pos = s.LastIndexOf("-"c)
Return If(pos = -1, 0, Integer.Parse(s.Substring(pos + 1)))
End Function
Dim arr() As String = New String() {"a.csv", "a-1.csv", "a-2.csv", "a-3.csv", "ab.csv", "ab-1.csv", "ab-2.csv", "cccc.csv", "cccc-1.csv", "d.csv"}
Dim largest = arr.GroupBy(Function(s) Suffix(s), StringComparer.OrdinalIgnoreCase) _
.Select(Function(g) g.OrderByDescending(Function(s) Value(s)).First())
For Each s In largest
Console.WriteLine(s)
Next
Though your question is not clear but I think you want to have the latest occurrence to be stored in a separate array. Here is how you can achieve that:
Dim arrayInput As List(Of String) = New List(Of String)
arrayInput.Add("a.csv")
arrayInput.Add("a-1.csv")
arrayInput.Add("a-2.csv")
arrayInput.Add("a-3.csv")
arrayInput.Add("b.csv")
arrayInput.Add("b-1.csv")
arrayInput.Add("b-2.csv")
arrayInput.Add("c.csv")
arrayInput.Add("c-1.csv")
arrayInput.Add("d.csv")
Dim arrayOutput As List(Of String) = New List(Of String)
Dim strTemp As String = arrayInput(0)
Dim startingChar As String = strTemp.Substring(0, 1)
For Each item As String In arrayInput
If Not startingChar.Equals(item.Substring(0, 1), StringComparison.OrdinalIgnoreCase) Then
arrayOutput.Add(strTemp)
startingChar = item.Substring(0, 1)
End If
strTemp = item
Next
arrayOutput.Add(strTemp)
You have the required result in arrayOutput. Let me know if you wanted something else instead.
In VB.NET, how can I convert the following string into some kind of key/value type such as a Hashtable, Dictionary, etc?
"Name=Fred;Birthday=19-June-1906;ID=12345"
I want to extract Birthday or ID without having to split the string into an array.
EDIT: I'd prefer not to split the string into an array in case the format of the string changes later. I don't have control over the string. What if someone switches the order around or adds another element?
I’m currently unable to test this, lacking a VB compiler, but the following solution should also work, and it has the advantage of not requiring an explicit loop. It uses the Linq method ToDictionary and two nested Split operations:
Dim s = "Name=Fred;Birthday=19-June-1906;ID=12345"
Dim d = s.Split(";"c).Select(Function (kvp) kvp.Split("="c)) _
.ToDictionary( _
Function (kvp) kvp(0), _
Function (kvp) kvp(1))
First, we split on the outer delimiter (i.e. the semi-colon). From the resulting array, we select by splitting again, this time on =. The resulting array of arrays is converted to a dictionary by specifying that the first item is to become the key and the second is to become the value (the identifier kvp stands for “key-value pair”).
Since I can’t check the exact VB syntax and the above may contain subtle errors, here is the equivalent C# code (tested for correctness):
var s = "Name=Fred;Birthday=19-June-1906;ID=12345";
var d = s.Split(';').Select(kvp => kvp.Split('='))
.ToDictionary(kvp => kvp[0], kvp => kvp[1]);
Not sure why you don't want to split it. If you're sure there won't be any extra = or ; then you could just do:
Dim s As String = "Name=Fred;Birthday=19-June-1906;ID=12345"
Dim d As New Dictionary(Of String, String)
For Each temp As String In s.Split(";"c)
Dim index As Int32 = temp.IndexOf("="c)
d.Add(temp.Substring(0, index), temp.Substring(index + 1))
Next
Which might not be beautiful, but is very easy to understand.
input.Split(";"c) returns an array of key/value:
{ "Name=Fred", "Birthday=19-June-1906" , "ID=12345" }
so pair.Split("="c) returns { "Name", "Fred" } etc
If you want an alternative to doing a String.Split; there is always Regular Expressions as an alternative:
Dim map As Dictionary(Of String, String) = New Dictionary(Of String, String)
Dim match As Match = Regex.Match("Name=Fred;Birthday=19-June-1906;ID=12345", "(?<Name>[^=]*)=(?<Value>[^;]*);?")
While (match.Success)
map.Add(match.Groups("Name").Value, match.Groups("Value").Value)
match = match.NextMatch()
End While
The regular expression itself could be beefed up to better handle whitespace between key/value's and pair's but you hopefully get the idea. This should only pass through the string once to build up a string dictionary of keys and values.
Dim persSeparator as string=";"
Dim keyValSeparator as string="=";
Dim allPersons As New Dictionary(Of String, Person)
Dim str As String = "Name=Fred;Birthday=19-June-1906;ID=12345"
Dim parts As New List(Of String)(str.Split(persSeparator.ToCharArray)) 'why dont want you to split this string??
Dim person As New Person
For Each part As String In parts
Dim keyValue() As String = part.Split(keyValSeparator.toCharArray())
Select Case keyValue(0).ToUpper
Case "ID"
person.ID = keyValue(1)
Case "NAME"
person.Name = keyValue(1)
Case "BIRTHDAY"
person.BirthDay= keyValue(1)
End Select
Next
If Not allPersons.ContainsKey(person.ID) Then
allPersons.Add(person.ID, person)
End If
Public Class Person
Private _name As String
Private _birthday As String
Private _id As String = String.Empty
Public Sub New()
End Sub
Public Sub New(ByVal id As String)
Me._id = id
End Sub
Public Sub New(ByVal id As String, ByVal name As String)
Me._id = id
Me._name = name
End Sub
Public Sub New(ByVal id As String, ByVal name As String, ByVal birthday As String)
Me._id = id
Me._name = name
Me._birthday = birthday
End Sub
Public Property ID() As String
Get
Return Me._id
End Get
Set(ByVal value As String)
Me._id = value
End Set
End Property
Public Property Name() As String
Get
Return Me._name
End Get
Set(ByVal value As String)
Me._name = value
End Set
End Property
Public Property BirthDay() As String
Get
Return Me._birthday
End Get
Set(ByVal value As String)
Me._birthday = value
End Set
End Property
Public Overrides Function Equals(ByVal obj As Object) As Boolean
If TypeOf obj Is Person AndAlso Not obj Is Nothing Then
Return String.Compare(Me._id, DirectCast(obj, Person).ID) = 0
Else : Return False
End If
End Function
End Class
If you were just wanting to extract the birthday and ID from the string and place as a value pair in some sort of dictionary, for simplicity I would use regular expressions and then a generic dictionary (of string, valuepair structure). Something like this:
Imports System.Text.RegularExpressions
Imports System.Collections.Generic
Sub Main()
Dim Person As New Dictionary(Of String, ValuePair)
Dim s As String = "Name=Fred;Birthday=19-June-1906;ID=12"
Dim r As Regex = New Regex("Name=(.*);Birthday=(.*);ID=(.*$)")
Dim m As Match = r.Match(s)
Person.Add(CStr(m.Groups(1).Value), _
New ValuePair(CDate(m.Groups(2).Value), CInt(m.Groups(3).Value)))
Console.WriteLine(Person("Fred").Birthday.ToString)
Console.WriteLine(Person("Fred").ID.ToString)
Console.Read()
End Sub
Friend Structure ValuePair
Private _birthday As Date
Private _ID As Int32
Public ReadOnly Property ID() As Int32
Get
Return _ID
End Get
End Property
Public ReadOnly Property Birthday() As Date
Get
Return _birthday
End Get
End Property
Sub New(ByVal Birthday As Date, ByVal ID As Int32)
_birthday = Birthday
_ID = ID
End Sub
End Structure