"Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
news:1154531218.502140.128060@h48g2000cwc.googlegroups.com...
> I'm looking for a simple way to unique an array of strings. I came up
> with this. Does it make sense? Am i missing anything? (Testing seems to
> show it to work.)
>
> Public Function Unique(ByVal List() As String) As String()
>
>        ' Returns the unique values of in array, in an array.
>
>        Dim Temp As New
> System.Collections.Specialized.StringCollection()
>
>        For Each Current_String As String In List
>            If Not Temp.Contains(Current_String) Then
> Temp.Add(Current_String)
>        Next
>
>        ReDim Unique(Temp.Count - 1)
>
>        Temp.CopyTo(Unique, 0)
>
> End Function
>
> B.
>

> "Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
> news:1154531218.502140.128060@h48g2000cwc.googlegroups.com...
> > I'm looking for a simple way to unique an array of strings. I came up
> > with this. Does it make sense? Am i missing anything? (Testing seems to
> > show it to work.)
> >
> > Public Function Unique(ByVal List() As String) As String()
> >
> >        ' Returns the unique values of in array, in an array.
> >
> >        Dim Temp As New
> > System.Collections.Specialized.StringCollection()
> >
> >        For Each Current_String As String In List
> >            If Not Temp.Contains(Current_String) Then
> > Temp.Add(Current_String)
> >        Next
> >
> >        ReDim Unique(Temp.Count - 1)
> >
> >        Temp.CopyTo(Unique, 0)
> >
> > End Function
> >
> > B.
> >
>
> Public Function Unique(ByVal List As String()) As String()
>     Dim temp As StringCollection = New StringCollection()
>
>     For Each current As String in List
>         If Not temp.Contains(current)
>             temp.Add(current)
>         End If
>     Next
>
>     Return temp
> End Function
>
> You don't need to ReDim Unique ... you could just use the "Return" statement
> to return the array.
> Shortened it up a wittle...and afaik, this would be how you remove duplicate
> array entries...
>
> HTH,
> Mythran

"Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
news:1154533868.444370.66540@h48g2000cwc.googlegroups.com...
> Mythran wrote:
>> "Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
>> news:1154531218.502140.128060@h48g2000cwc.googlegroups.com...
>> > I'm looking for a simple way to unique an array of strings. I came up
>> > with this. Does it make sense? Am i missing anything? (Testing seems to
>> > show it to work.)
>> >
>> > Public Function Unique(ByVal List() As String) As String()
>> >
>> >        ' Returns the unique values of in array, in an array.
>> >
>> >        Dim Temp As New
>> > System.Collections.Specialized.StringCollection()
>> >
>> >        For Each Current_String As String In List
>> >            If Not Temp.Contains(Current_String) Then
>> > Temp.Add(Current_String)
>> >        Next
>> >
>> >        ReDim Unique(Temp.Count - 1)
>> >
>> >        Temp.CopyTo(Unique, 0)
>> >
>> > End Function
>> >
>> > B.
>> >
>>
>> Public Function Unique(ByVal List As String()) As String()
>>     Dim temp As StringCollection = New StringCollection()
>>
>>     For Each current As String in List
>>         If Not temp.Contains(current)
>>             temp.Add(current)
>>         End If
>>     Next
>>
>>     Return temp
>> End Function
>>
>> You don't need to ReDim Unique ... you could just use the "Return"
>> statement
>> to return the array.
>> Shortened it up a wittle...and afaik, this would be how you remove
>> duplicate
>> array entries...
>>
>> HTH,
>> Mythran
>
> Thanx for the feedback.
>
> Hmm.. aren't you returning a StringCollection, when the Function
> declared an array of String? Is there a way to do that? I put it back
> into an array to return the same type.
>
> As for the Redim, i thought it would be nicer to explicitly set the
> size. But mostly, VB didn't like me using the function name without
> doing something with it first (the green line, and at run time i got an
> error about not instantiating it yet.)
>
> B.
>

> "Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
> news:1154533868.444370.66540@h48g2000cwc.googlegroups.com...
> > Mythran wrote:
> >> "Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
> >> news:1154531218.502140.128060@h48g2000cwc.googlegroups.com...
> >> > I'm looking for a simple way to unique an array of strings. I came up
> >> > with this. Does it make sense? Am i missing anything? (Testing seems to
> >> > show it to work.)
> >> >
> >> > Public Function Unique(ByVal List() As String) As String()
> >> >
> >> >        ' Returns the unique values of in array, in an array.
> >> >
> >> >        Dim Temp As New
> >> > System.Collections.Specialized.StringCollection()
> >> >
> >> >        For Each Current_String As String In List
> >> >            If Not Temp.Contains(Current_String) Then
> >> > Temp.Add(Current_String)
> >> >        Next
> >> >
> >> >        ReDim Unique(Temp.Count - 1)
> >> >
> >> >        Temp.CopyTo(Unique, 0)
> >> >
> >> > End Function
> >> >
> >> > B.
> >> >
> >>
> >> Public Function Unique(ByVal List As String()) As String()
> >>     Dim temp As StringCollection = New StringCollection()
> >>
> >>     For Each current As String in List
> >>         If Not temp.Contains(current)
> >>             temp.Add(current)
> >>         End If
> >>     Next
> >>
> >>     Return temp
> >> End Function
> >>
> >> You don't need to ReDim Unique ... you could just use the "Return"
> >> statement
> >> to return the array.
> >> Shortened it up a wittle...and afaik, this would be how you remove
> >> duplicate
> >> array entries...
> >>
> >> HTH,
> >> Mythran
> >
> > Thanx for the feedback.
> >
> > Hmm.. aren't you returning a StringCollection, when the Function
> > declared an array of String? Is there a way to do that? I put it back
> > into an array to return the same type.
> >
> > As for the Redim, i thought it would be nicer to explicitly set the
> > size. But mostly, VB didn't like me using the function name without
> > doing something with it first (the green line, and at run time i got an
> > error about not instantiating it yet.)
> >
> > B.
> >
>
> woops, in this case I would do the following :D
>
> Public Function Unique(ByVal List As String()) As String()
>     Dim temp As ArrayList = New ArrayList()
>
>     For Each current As String in List
>         If Not temp.Contains(current)
>             temp.Add(current)
>         End If
>     Next
>
>     Return DirectCast(temp.ToArray(GetType(String)), String())
> End Function
>
>
> :D  That's what I get for not testing it heh..
>
> HTH,
> Mythran

>> woops, in this case I would do the following :D
>>
>> Public Function Unique(ByVal List As String()) As String()
>>     Dim temp As ArrayList = New ArrayList()
>>
>>     For Each current As String in List
>>         If Not temp.Contains(current)
>>             temp.Add(current)
>>         End If
>>     Next
>>
>>     Return DirectCast(temp.ToArray(GetType(String)), String())
>> End Function
>>
>>
>> :D  That's what I get for not testing it heh..
>>
>> HTH,
>> Mythran
>
> Kewl. I didn't realize i could use an ArrayList here. A bit nicer.
>
> With about an array(1000000) with about 400,000 entries (just my quikie
> test) ArrayList was about 1/100 of a second faster. (Tested without
> DirectCast.)
>
> What's the DirectCast for?  The help also does it (well, it uses
> CType()) but ToArray() itself is casting it. Why cast it again?
>
> B.
>

> >> woops, in this case I would do the following :D
> >>
> >> Public Function Unique(ByVal List As String()) As String()
> >>     Dim temp As ArrayList = New ArrayList()
> >>
> >>     For Each current As String in List
> >>         If Not temp.Contains(current)
> >>             temp.Add(current)
> >>         End If
> >>     Next
> >>
> >>     Return DirectCast(temp.ToArray(GetType(String)), String())
> >> End Function
> >>
> >>
> >> :D  That's what I get for not testing it heh..
> >>
> >> HTH,
> >> Mythran
> >
> > Kewl. I didn't realize i could use an ArrayList here. A bit nicer.
> >
> > With about an array(1000000) with about 400,000 entries (just my quikie
> > test) ArrayList was about 1/100 of a second faster. (Tested without
> > DirectCast.)
> >
> > What's the DirectCast for?  The help also does it (well, it uses
> > CType()) but ToArray() itself is casting it. Why cast it again?
> >
> > B.
> >
>
> ToArray places all items in the ArrayList into an array and returns the
> array as an object array.  I am using DirectCast to cast from an object
> array to a string array :)  Sure, if you don't have Option Strict turned on,
> it would perform the casting automatically, but I have a habit of turning on
> Option Strict for my projects :)
>
> HTH,
> Mythran

"Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
news:1154695691.221359.159860@m79g2000cwm.googlegroups.com...
>
> Mythran wrote:
>> >> woops, in this case I would do the following :D
>> >>
>> >> Public Function Unique(ByVal List As String()) As String()
>> >>     Dim temp As ArrayList = New ArrayList()
>> >>
>> >>     For Each current As String in List
>> >>         If Not temp.Contains(current)
>> >>             temp.Add(current)
>> >>         End If
>> >>     Next
>> >>
>> >>     Return DirectCast(temp.ToArray(GetType(String)), String())
>> >> End Function
>> >>
>> >>
>> >> :D  That's what I get for not testing it heh..
>> >>
>> >> HTH,
>> >> Mythran
>> >
>> > Kewl. I didn't realize i could use an ArrayList here. A bit nicer.
>> >
>> > With about an array(1000000) with about 400,000 entries (just my quikie
>> > test) ArrayList was about 1/100 of a second faster. (Tested without
>> > DirectCast.)
>> >
>> > What's the DirectCast for?  The help also does it (well, it uses
>> > CType()) but ToArray() itself is casting it. Why cast it again?
>> >
>> > B.
>> >
>>
>> ToArray places all items in the ArrayList into an array and returns the
>> array as an object array.  I am using DirectCast to cast from an object
>> array to a string array :)  Sure, if you don't have Option Strict turned
>> on,
>> it would perform the casting automatically, but I have a habit of turning
>> on
>> Option Strict for my projects :)
>>
>> HTH,
>> Mythran
>
> But isn't that only if you do not specify the Tyope in ToArray()?
>
> According to the help: <URL:
> ms-help://MS.MSDNQTR.v80.en/MS.MSDN.v80/MS.NETDEVFX.v20.en/cpref2/html/M_System_Collections_ArrayList_ToArray_1_a6998a77.htm>
>
> ArrayList.ToArray Method (Type)
> ...
> Copies the elements of the ArrayList to a new array of the specified
> element type.
> ...
> Parameters
> type
> The element Type of the destination array to create and copy elements
> to
>
> Return Value
> An array of the specified element type containing copies of the
> elements of the ArrayList.
>
> What am i missing?
>
> B.
>

> "Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
> news:1154695691.221359.159860@m79g2000cwm.googlegroups.com...
> >
> > Mythran wrote:
> >> >> woops, in this case I would do the following :D
> >> >>
> >> >> Public Function Unique(ByVal List As String()) As String()
> >> >>     Dim temp As ArrayList = New ArrayList()
> >> >>
> >> >>     For Each current As String in List
> >> >>         If Not temp.Contains(current)
> >> >>             temp.Add(current)
> >> >>         End If
> >> >>     Next
> >> >>
> >> >>     Return DirectCast(temp.ToArray(GetType(String)), String())
> >> >> End Function
> >> >>
> >> >>
> >> >> :D  That's what I get for not testing it heh..
> >> >>
> >> >> HTH,
> >> >> Mythran
> >> >
> >> > Kewl. I didn't realize i could use an ArrayList here. A bit nicer.
> >> >
> >> > With about an array(1000000) with about 400,000 entries (just my quikie
> >> > test) ArrayList was about 1/100 of a second faster. (Tested without
> >> > DirectCast.)
> >> >
> >> > What's the DirectCast for?  The help also does it (well, it uses
> >> > CType()) but ToArray() itself is casting it. Why cast it again?
> >> >
> >> > B.
> >> >
> >>
> >> ToArray places all items in the ArrayList into an array and returns the
> >> array as an object array.  I am using DirectCast to cast from an object
> >> array to a string array :)  Sure, if you don't have Option Strict turned
> >> on,
> >> it would perform the casting automatically, but I have a habit of turning
> >> on
> >> Option Strict for my projects :)
> >>
> >> HTH,
> >> Mythran
> >
> > But isn't that only if you do not specify the Tyope in ToArray()?
> >
> > According to the help: <URL:
> > ms-help://MS.MSDNQTR.v80.en/MS.MSDN.v80/MS.NETDEVFX.v20.en/cpref2/html/M_System_Collections_ArrayList_ToArray_1_a6998a77.htm>
> >
> > ArrayList.ToArray Method (Type)
> > ...
> > Copies the elements of the ArrayList to a new array of the specified
> > element type.
> > ...
> > Parameters
> > type
> > The element Type of the destination array to create and copy elements
> > to
> >
> > Return Value
> > An array of the specified element type containing copies of the
> > elements of the ArrayList.
> >
> > What am i missing?
> >
> > B.
> >
>
> The ToArray method does not return an object() as I originally mentioned.
> The type returned is System.Array.  When you have Option Strict turned on,
> you can not set a string-array to <instance of ArrayList>.ToArray( ... ) .
> The compiler will give you errors (I did, in fact, test this part out).
>
> Otherwise, yes you are correct that it does create a string array (or array
> of the specified type passed into ToArray).
>
> Dim array As Array = list.ToArray(GetType(String))
> Console.WriteLine(array)   ' Returns String[]
>
> Mythran

"Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
news:1154710116.768954.57630@p79g2000cwp.googlegroups.com...
>
> Mythran wrote:
>> "Brian Tkatch" <Maxwell_Sm***@ThePentagon.com> wrote in message
>> news:1154695691.221359.159860@m79g2000cwm.googlegroups.com...
>> >
>> > Mythran wrote:
>> >> >> woops, in this case I would do the following :D
>> >> >>
>> >> >> Public Function Unique(ByVal List As String()) As String()
>> >> >>     Dim temp As ArrayList = New ArrayList()
>> >> >>
>> >> >>     For Each current As String in List
>> >> >>         If Not temp.Contains(current)
>> >> >>             temp.Add(current)
>> >> >>         End If
>> >> >>     Next
>> >> >>
>> >> >>     Return DirectCast(temp.ToArray(GetType(String)), String())
>> >> >> End Function
>> >> >>
>> >> >>
>> >> >> :D  That's what I get for not testing it heh..
>> >> >>
>> >> >> HTH,
>> >> >> Mythran
>> >> >
>> >> > Kewl. I didn't realize i could use an ArrayList here. A bit nicer.
>> >> >
>> >> > With about an array(1000000) with about 400,000 entries (just my
>> >> > quikie
>> >> > test) ArrayList was about 1/100 of a second faster. (Tested without
>> >> > DirectCast.)
>> >> >
>> >> > What's the DirectCast for?  The help also does it (well, it uses
>> >> > CType()) but ToArray() itself is casting it. Why cast it again?
>> >> >
>> >> > B.
>> >> >
>> >>
>> >> ToArray places all items in the ArrayList into an array and returns
>> >> the
>> >> array as an object array.  I am using DirectCast to cast from an
>> >> object
>> >> array to a string array :)  Sure, if you don't have Option Strict
>> >> turned
>> >> on,
>> >> it would perform the casting automatically, but I have a habit of
>> >> turning
>> >> on
>> >> Option Strict for my projects :)
>> >>
>> >> HTH,
>> >> Mythran
>> >
>> > But isn't that only if you do not specify the Tyope in ToArray()?
>> >
>> > According to the help: <URL:
>> > ms-help://MS.MSDNQTR.v80.en/MS.MSDN.v80/MS.NETDEVFX.v20.en/cpref2/html/M_System_Collections_ArrayList_ToArray_1_a6998a77.htm>
>> >
>> > ArrayList.ToArray Method (Type)
>> > ...
>> > Copies the elements of the ArrayList to a new array of the specified
>> > element type.
>> > ...
>> > Parameters
>> > type
>> > The element Type of the destination array to create and copy elements
>> > to
>> >
>> > Return Value
>> > An array of the specified element type containing copies of the
>> > elements of the ArrayList.
>> >
>> > What am i missing?
>> >
>> > B.
>> >
>>
>> The ToArray method does not return an object() as I originally mentioned.
>> The type returned is System.Array.  When you have Option Strict turned
>> on,
>> you can not set a string-array to <instance of ArrayList>.ToArray( ... )
>> .
>> The compiler will give you errors (I did, in fact, test this part out).
>>
>> Otherwise, yes you are correct that it does create a string array (or
>> array
>> of the specified type passed into ToArray).
>>
>> Dim array As Array = list.ToArray(GetType(String))
>> Console.WriteLine(array)   ' Returns String[]
>>
>> Mythran
>
> So, then, to be clear, in the example you provided:
>
> Return DirectCast(temp.ToArray(GetType(String)), String())
>
> is the DirectCast extra or not?
>
> BTW, thanx for all the detailed responses.
>
> B.
>