Given the following array as an example...
arr(0)(0) = 3
arr(0)(1) = name
arr(0)(2) = address
arr(1)(0) = 7
arr(1)(1) = name
arr(1)(2) = address
arr(2)(0) = 14
arr(2)(1) = name
arr(2)(2) = address
I need to delete the middle element (id=7) from the array. I understand that I need to loop through the array and move each record that isnt to be deleted into a new array. I tried like this...
Dim newArr,i
Redim newArr(Ubound(arr))
For i = 0 to Ubound(arr)
If (CStr(arr(i)(0)) <> 7 ) Then
newArr(i) = arr(i)
End if
Next
When debugging this I can see the if statement work so I know only 2 elements are copied but newArr is empty at the end of this. What am I missing. I am a PHP coder that is new to classic asp and Im used to having array functions that make this kind of thing unnecessary. Any help appreciated. Thank you.
You don't need new array, you can just reassign the items and "crop" the array:
Const removalIndex = 1
For x=removalIndex To UBound(arr)-1
arr(x) = arr(x + 1)
Next
ReDim Preserve arr(UBound(arr) - 1)
This code will remove the array item at index 1 from the main array. If you don't know in advance the index of the item to remove, you can easily find it with a simple loop over the array.
Instead of using array you can give Scripting.Dictionary a try.
It is much more flexible, and has, among others Remove method.
I suggest using Scripting.Dictionary and using it as a List/collection instead, as it allows for insertions and deletions. See here: Lists in VBScript
I don't know the definitive answer, but if I were to take a stab in the dark guess I'd suggest that since the array is two dimensional maybe you have to explicitly refer to it that way?
Dim newArr,i
Redim newArr(Ubound(arr),3)
For i = 0 to Ubound(arr)
If (CStr(arr(i)(0)) <> 7 ) Then
newArr(i)(0) = arr(i)(0)
newArr(i)(1) = arr(i)(1)
newArr(i)(2) = arr(i)(2)
End if
Next
I see some VBScript syntax issues. First:
arr(0)(0) = 3 'ERROR: Subscript out of range
arr(0, 0) = 3 'CORRECT
Next:
ReDim newArr(Ubound(arr)) 'this is 1 dimensional array
newArr(0) = arr(0) 'this will NOT work
newArr(0) = arr(0, 0) 'this will work
And finally: why you convert to String and then compare it to an Integer with:
(CStr(arr(i)(0)) <> 7)
Related
I cannot explain well in the title so i'll explain here the scenario:
In here, i have a query that will be placed in an array.
Dim arrUsers As Object = {{sqlReader("dephead"), dropdown1}, {sqlReader("mm"), dropdown2}
I want to enable the dropdown object if it matches my if else condition:
'indexes1= the 1st indexes of each pair in the array (the sqlReaders)
'indexes2= my dropdown objects in my user control
For Each indexes1 In arrUsers
If Session.Item("EmployeeID") = indexes1 Then
indexes2.Enabled = True
End If
Next
so lets say the my session id will be "dephead", then the dropdown1 will be enabled. Thats what i would like to happen but im not familiar on arrays so kindly help me. Thanks.
This should work:
For i As Integer = 0 to arrUsers.GetUpperBound(0)
If Session.Item("EmployeeID") = arrUsers(i)(0) Then
arrUsers(i)(1).Enabled = True
End If
Next
You simply give the array two indexes instead of one. arrUsers(0)(1), for example. The first index returns the object at that index, and the second index returns the object inside the previously returned array. arrUsers(0)(1) will first grab the array at 0 index ({sqlReader("dephead"), dropdown1}), then get the object at index 1 (dropdown1).
This answered my question. The answer above helped me and i just changed the declaration of my arrays and changed some syntax.
Dim arrUsers(,) As Object =
New Object(,) {
{sqlReader("dephead"), dropdown1}, _
{sqlReader("mm"), dropdown2}, _
}
Dim bound0 As Integer = arrUsers.GetUpperBound(0)
Dim bound1 As Integer = arrUsers.GetUpperBound(1)
For i As Integer = 0 To bound0
If Session.Item("EmployeeID") = arrUsers(i, 0) Then
arrUsers(i, 1).Enabled = True
End If
Next
is there a way of calling a specific list of lists without having to check (or loop) them all?
it is easier to understand with an example....
lets say
callList(5).key = "1234"
callList(5).callOpened = "11/26/13"
now i want to do something like
textbox_callOpened.text = callList(where key = "1234").callOpened
i also need to know what index that was at for there are many more items that i need to output too.
You can use LINQ. Add Imports System.Linq at top of the file and use First method with lambda expression as a predicate to get what you need:
' that gives you item matching your predicate '
Dim item = callList.First(Function(x) x.Key = "1234")
' you can use it to set the property '
textbox_callOpened.text = item.callOpened
pseudo code, didn't test but should work
dim something = callList.firstordefault(function(d) d.key = "1234")
if something is not nothing then
textbox_callOpened.text = something.callOpened
else
'cant find an element with key 1234
end if
A tons of advance thanks to everybody for taking time on this!
Am I doning this correctly? it says "Parameter count mismatch." for SetValue method
For i = 0 To (missingFieldName.Count) - 1
Dim propertyiInfo As System.Reflection.PropertyInfo =
GetType(ImportFields).GetProperty(missingValuesTakenfromUser.missingFieldAcquired(i, 0))
Dim fieldacquired As String = missingValuesTakenfromUser.missingFieldAcquired(i, 1)
propertyiInfo.SetValue(fields, fieldacquired, New Object() {0})
Next i
fields is an instance of class ImportFields. tried a 100 different ways to work with this in last 2 days. desperately looking for a solution, please someone?
For a non-indexed property, the third parameter should be null, not an empty array. Try this:
propertyiInfo.SetValue(fields, fieldacquired, null);
If you use .net 4.5, there's a new overload with only two parameters that you can use instead:
propertyiInfo.SetValue(fields, fieldacquired); // .net 4.5 only
Got it after 4 days continuous struggle. here is how to do that
Many thanks to Jods for giving a tip above.
For i = 0 To (missingFieldName.Count) - 1
Dim propertyiInfo As System.Reflection.PropertyInfo =
GetType(ImportFields).GetProperty(missingValuesTakenfromUser.missingFieldAcquired(i, 0))
Dim fieldacquired As String = missingValuesTakenfromUser.missingFieldAcquired(i, 1)
propertyiInfo.GetValue(fields, Nothing)(0) = fieldacquired
Next i
actually, MS is a bit confusing when they say indexed items. it meant to me they referring to array.
thanks a lot for everybody who struggled to solve this for me.
Im looking for help with trying to vary a variable-name in a for loop:
For b = 1 To Count
' the below image_var(b) varible needs to vary on each iteration'
Dim image_var(b) As New LinkedResource(Server.MapPath(myArray(b-1)))
' need also to have the b in myArray(b-1) bit work through the loop too'
' that is I''m after the array index b minus 1'
image_var(b).ContentId = "imageContentId_" + b.ToString
' add the LinkedResource to the appropriate view'
htmlView.LinkedResources.Add(image_var(b))
Next b
Thanks in advance as I can't logon to accept an answer...
Thanks Guffa - my pics are now making it through to the email and showing up.
The (b) in the image_var(b) was just a stub for me too - till I found the code I was after... Am new and didn't even know/realise that it made an array... am a nobb.
Thanks again...
I don't know why you think that you need a separate variable for each instance. The variable just holds a reference to the object, it doesn't matter at all what you call the variable. You can just reuse the same variable for each of the objects:
For b = 1 To Count
Dim image As New LinkedResource(Server.MapPath(myArray(b-1)))
image.ContentId = "imageContentId_" + b.ToString
' add the LinkedResource to the appropriate view'
htmlView.LinkedResources.Add(image)
Next b
I'm making a fair amount of calls to database tables via ADO.
In the spirit of keeping things DRY, I wrote the following functions to return an array of values from a recordset.
Is this hare brained?
I use it mainly for grabbing a set of combo-box values and the like, never for enormous values. Example Usage (error handling removed for brevity):
Function getEmployeeList()
getEmployeeList= Array()
strSQL = "SELECT emp_id, emp_name from employees"
getEmployeeList = getSQLArray( strSQL, "|" )
End Function
Then I just do whatever I want with the returned array.
Function getSQLArray( SQL, delimiter )
'*************************************************************************************
' Input a SQL statement and an optional delimiter, and this function
' will return an array of strings delimited by whatever (pipe defaults)
' You can perform a Split to extract the appropriate values.
' Additionally, this function will return error messages as well; check for
' a return of error & delimiter & errNum & delimiter & errDescription
'*************************************************************************************
getSQLArray = Array()
Err.Number = 0
Set objCon = Server.CreateObject("ADODB.Connection")
objCon.Open oracleDSN
Set objRS = objCon.Execute(SQL)
if objRS.BOF = false and objRS.EOF = false then
Do While Not objRS.EOF
for fieldIndex=0 to (objRS.Fields.Count - 1)
If ( fieldIndex <> 0 ) Then
fieldValue = testEmpty(objRS.Fields.Item(fieldIndex))
recordString = recordString & delimiter & fieldValue
Else
recordString = CStr(objRS.Fields.Item(fieldIndex))
End If
Next
Call myPush( recordString, getSQLArray )
objRS.MoveNext
Loop
End If
Set objRS = Nothing
objCon.Close
Set objCon = Nothing
End Function
Sub myPush(newElement, inputArray)
Dim i
i = UBound(inputArray) + 1
ReDim Preserve inputArray(i)
inputArray(i) = newElement
End Sub
Function testEmpty( inputValue )
If (trim( inputValue ) = "") OR (IsNull( inputValue )) Then
testEmpty = ""
Else
testEmpty = inputValue
End If
End Function
The questions I'd have are:
Does it make sense to abstract all the recordset object creation/opening/error handling into its own function call like this?
Am I building a Rube Goldberg machine, where anyone maintaining this code will curse my name?
Should I just suck it up and write some macros to spit out the ADO connection code, rather than try doing it in a function?
I'm very new to asp so I have holes in its capabilities/best practices, so any input would be appreciated.
There's nothing wrong with doing it your way. The ADO libraries were not really all that well designed, and using them directly takes too many lines of code, so I always have a few utility functions that make it easier to do common stuff. For example, it's very useful to make yourself an "ExecuteScalar" function that runs SQL that happens to return exactly one value, for all those SELECT COUNT(*)'s that you might do.
BUT - your myPush function is extremely inefficient. ReDim Preserve takes a LONG time because it has to reallocate memory and copy everything. This results in O(n2) performance, or what I call a Shlemiel the Painter algorithm. The recommended best practice would be to start by dimming, say, an array with room for 16 values, and double it in size whenever you fill it up. That way you won't have to call ReDim Preserve more than Lg2n times.
I wonder why you are not using GetRows? It returns an array, you will find more details here: http://www.w3schools.com/ado/met_rs_getrows.asp
A few notes on GetRows:
Set objRS = Server.CreateObject ("ADODB.Recordset")
objRS.Open cmd, , adOpenForwardOnly, adLockReadOnly
If Not objRS.EOF Then
astrEmployees = objRS.GetRows()
intRecFirst = LBound(astrEmployees, 2)
intRecLast = UBound(astrEmployees, 2)
FirstField = 0
SecondField = 1
End If
'2nd field of the fourth row (record) '
Response.Write (SecondField, 3)
Yes, it makes sense to factor out common tasks. I don't see anything wrong with the general idea. I'm wondering why you're returning an array of strings separated by a delimiter; you might as well return an array of arrays.