I'm trying so hard to initialize an array or arrayList of strings from a file while using a loop, but every function I'm using- put/enter/force nothing seems to work. the array time after time got filled with the last string I read even though I'm accessing a specific index that I increasing every iteration.
(I tried to add regular constant string and it worked well, I don't understand the difference.
Thanks to everyone who would help.
tArray:ARRAY[STRING] -- declaring
create tArray.make_empty
readingFile() --function
local
k:INTEGER_32
do
from k:=0
until curFile.end_of_file
loop
curFile.read_line
curLine:=curFile.last_string
tArray.force (curLine, k)
--tArray.put(curLine, k)
--tArray.enter (curLine, k)
--tArray.at (k):=curLine
--tArray.force ("sara", k+1)
k:=k+1
end
end
The feature read_line does not create a new string object every time, but rather reuses the last one. In other words, last_string always refers to the same object. The solution is to use a clone of the object associated with last_string at every iteration:
curLine := curFile.last_string.twin
Apologies if I am making some amateur mistakes, but I am new to VBA.
I'm trying to populate an array declared inside of a class as a property, but something's going wrong. After much searching I have two questions that I can't seem to find anywhere else:
1 - Is there a simpler way to accomplish saving data to an array-like structure that I can pass to functions from a sub? The array-like structure needs to be resizable because I will not know how many components I will add until each iteration of a loop checks those conditions.
2 - How do I correctly accomplish the passing of the array property in my class correctly to another function? It's frustrated me enough that I would like to know how it can be done if only to understand what I was doing wrong or, perhaps, what misunderstanding I had of the way VBA works.
Code structure follows:
I have declared a Segments property inside of a CTask class like this:
Private pSegments() As CSegment
Public Property Get Segments() As CSegment()
Segments = pSegments()
End Property
Public Property Get segment(index As Integer) As CSegment
segment = pSegments(index)
End Property
Public Property Let Segments(Value() As CSegment)
pSegments() = Value()
End Property
I pass the CTask from a Sub, where it is defined to populateTasks using this code:
Dim tasks() As CTask
ReDim tasks(1 To 10)
Call populateTasks(tasks)
When I do this, the populateTasks code receives it using the following code:
Function populateTasks(ByRef tasks() As CTask)
I then try to call another function from populateTasks called populateSegments like this:
Call populateSegments(tasks(icount).Segments)
I receive segments array inside populateSegments like this:
Function populateSegments(ByRef Segments() As CSegment)
The last two code snippets are where the problem resides. The segments array is populating correctly inside the populateSegments function, but when I check the array to see if it is empty just below the call to populateSegments there isn't anything in the tasks(icount).segments array. Thanks in advance for any help, and please let me know if more information is required.
Couldn't you make populatesegments a method of cTask? That avoids the problem and is a better design
When I rebuild the solution I get the warning:
"Variable 'aMyArray' is used before it has been assigned a value."
A function in VB.NET uses an array which is dynamically populated.
Example:
Function MyArray()
Try
Dim aMyArray()
For i = 0 to 100
ReDim Preserve aMyArray(i)
Next
Catch ex As Exception
End Try
End Function
How should I declare a dynamically populated array to eliminate this warning?
I like to use the CreateInstance to avoid possible errors:
Dim aMyArray() as string = Array.CreateInstance(GetType(String),0)
A. Your function returns nothing, so you should also have a warning about that
B. You seriously need to turn on Option Strict and let the compiler point out other errors like aMyArray has no Type.
C. Never use and empty Try/Catch; if there is an exception, you want to know when something goes wrong (and where) so you can fix it.
D. Avoid arrays like the plague. ReDim Preserve aMyArray(i) creates a new array and then copies all the data to the new structure. This can be costly in terms of performance if it is a large array of something like strings. Net has several very nice collections such as List(of T) which do not need to be explicitly resized:
Private myList As New List(of String) ' or Integer, Decimal or even MyClassObject
...
myList.Add("Hello")
myList.Add("Lists...")
myList.Add("Goodbye")
myList.Add("Arrays")
D(1). The result of using a List would mean that entire procedure can be done away with. Just add new things to the list as needed.
E. The code posted cant actually result in the warning because you dont ever add a value to it. Adding: aMyArray(2) = 2 after the loop will result in the warning. This is because you have never fully declared the array (size and type) as in:
Dim aMyArray(100) As String
ReDim simply resizes the array which isnt the same thing.
F. Since there is nothing in your new array, there is no reason to use ReDim Preserve because there is nothing to preserve. I'll assume that is supposed to be some calculation. On the other hand, if you are trying to resize an existing array, it should be a Sub.
We are all left to guess if it really is meant to modify an existing array (based on ReDim Preserve) or return a new array of stuff (considering the array is declared in the procedure).
Again, none of this is needed using a List, Dictionary or other Collection Type.
I want to know the fastest way to check if an array is empty in VB.NET. The array is already initialized so I can't use any of the checks that look at that. This is the current code below:
If Not (cubes(threadnumber)(i).objects.GetLength(0) = 0) Then
cubes(threadnumber)(i).objects = New Double() {}
ReDim cubes(threadnumber)(i).objects(-1)
End If
I've done some testing and I know that using .GetUpperBound is a little faster, but I'm not sure if this will work because I think .GetUpperBound returns a 0 if the array length is 1.
Any/all methods to speed this up (even fractionally) will be tremendously helpful. This program takes ages to compleate and the first line of the above code is a big portion of the time, it's called 136 million times.
Also if anyone knows how to speed up For...Next loops that'd be great too!
Length is about 2x faster than GetLength on my system (calling Length 136M times takes 0.650 seconds, while calling GetLength (0) takes 1.480 seconds).
I also do not understand why you ReDim your array, you've already created a new one.
I believe this will be the fastest code if cubes is a multi-dimensional array:
If cubes(threadnumber)(i).objects.Length > 0 Then
cubes(threadnumber)(i).objects = New Double() {}
End If
If cubes is not a multi-dimensional array (like List for instance), you should take the cubes(threadnumber) code out of the loop.
Update
Length is 6x faster than GetLength when running in Release mode without the debugger, in which case Length takes 0.181s and GetLength 1.175s on my system. This is likely because the JIT will inline the call to Length, but not the call to GetLength.
This is the test code I used.
if myarray is nothing then...
or
if myarray isnot nothing then...
GetLength is the fastest way I know of to see if an array has elements in it. I don't think you will speed up this piece of code.
However, the code that is calling this 136 million times could probably be optimised.
Looking at your code:
If Not (cubes(threadnumber)(i).objects.GetLength(0) = 0) Then
cubes(threadnumber)(i).objects = New Double() {}
ReDim cubes(threadnumber)(i).objects(-1)
End If
I'm guessing that the reason you are testing if it has elements is so you can redim the array to free up memory. A better way to free up memory might be to clear the cubes object instead and allow the arrays to fall out of scope.
After some intensive testing and analyzing I've found what appears to be the quickest method (so far at least). Making this small change has sped up my program 500-600%.
When there is an item added to the object arrays I also add the index of the second dimension of the cubes to a list IF the index of the second dimension is not already in the list. Any other suggest would be welcome though.
Question: I am wondering which is the optimal solution for dealing with Arrays in Excel 2003 VBA
Background: I have a Macro in Excel 2003 that is over 5000 lines. I have built it over the last 2 years adding new features as new Procedures, which helps to segment the code and debug, change, or add to that feature. The downside is that I am using much of the same base information in multiple procedures, which requires me to load it into arrays with minor differences multiple times. I am now running into issues with the length of run time, so I am now able to do a full rewrite.
This file is used to grab multiple items of manufacturing flows (up to 4 different set ups with a total of up to 10 distinct flows , of up to 1000 steps each) with the information being Flow specific, Sub-Flow specific for grouping / sorting purposes, and Data (such as movements, inventory, CT, ...)
It then will stick the data onto multiple sheets used to manage the process utilizing data sheets to be perused, charts, and Cell Formatting to denote process flow capability / history.
The Flow is in the Excel File, while the Manufacturing data is read in with 7 different OO4O Oracle SQL pulls, some reused multiple times
The Arrays are:
arrrFlow(1 to 1000, 1 to 4) as a Record Type with 4 strings
arrrSubFlow(1 to 1000, 1 to 10) as a Record Type with 4 strings, 2 integers, and 1 single
arrrData(1 to 1000, 1 to 10) as a Record Type with 1 string, 4 integers, 12 longs, and 1 single
arriSort(1 to 1000, 1 to 4) as Integer (Used as a pointer Array to sort the Flow, Sub Flow, and Data in a Group, Sub Group, and Step order while leaving the original arrays in Step order)
Possibilities:
1) Rewrite the macro into one big procedure that loads the data into master arrays dimensioned within the Procedure once
Pro: Dimensioned in the Procedure rather than as a Public Variable in the Module and not passed.
Con: Harder to debug with one mega procedure instead of multiple smaller ones.
2) Keep macro with multiple procedures but passing the Arrays
Pro: Easier to debug code with multiple smaller procedures.
Con: Passing Arrays (Expensive?)
3) Keep macro with multiple procedures but with the Arrays being Public Dim'ed variables in the Module
Pro: Easier to debug code with multiple smaller procedures.
Con: Public Arrays (Expensive?)
So, what's the community's verdict? Does anyone know the expense of using Public Arrays vs Passing Arrays? Is the Cost of either of these worth losing the ease of having my procedures being focused on one feature?
UPDATE:
I load Inventory Data at a discrete level (multiple per Step), Moves Data at a aggregate level (one per step), and the Beginning of Shift Inventory at an aggregate level. I aggregate the Inventory data by step placing it in Work State categories (Run, Wait,...) I create targets off data already on the sheets.
I have a Flow sheet that shows the Work Flows by Type, currently 3 products have a similar but not exactly the same flow, and 2 products are a different flow, that are similar but again not the same as each other. I have assigned each set of steps in the different flows a group and sub-group.
I place this data on multiple sheets, some in Step Order, some in group / sub-group order. I also need the data summed up by group and product, group / sub-group and product, portion of the line and product, and product.
I use Record Types so I actually have a readable three dimensional array, arrSubFlow(1,1).strStep (Step Name of the 1st Step of the 1st Device), arrData(10,5).lngYest (Yesterday's movement for the 10th Step of the 5th Device).
My main point of optimization is going to be in the section where I create 10 pages from scratch every single time. With Merging Cells, Borders, Headers, ... This is a very time consuming process. I will add a section that will compare my data with the page to see if it needs to be changed and if so, only then recreate it otherwise, I'll clear each section of data and only write data that changes to the sheet. This will be huge, based on my time logging data. However, whenever I update code, I always try to improve other aspects of the code as well. I see the loading of the data into a Structure (Array, RecordSet, Collection) once as both a little bit of optimization, but more so for data integrity, so I do not have the opportunity to load it differently for different sheets.
The main issues I see getting away from Arrays right now are:
* Already heavily invested in them, but this is not a good enough reason to not change
* Don't know if there is much cost to passing them, since it will by ByRef
* I use a Sort Function to create a Sorted "Pointer" array that lets me leave the Array in Step Flow order, while easily referencing it by Group / Sub-group order.
Since I am always trying to make my code for now and the future, I am not against updating the arrays to either RecordSets or Collections, but not merely for the sake of changing them to learn something cool. My arrays work and from my research, they add seconds to the run time, not substantial amounts for this 2 minute report. So If another structure is easier to update in the future than Two-dimensional Arrays of Record Types, then please let me know, but does anyone know the cost of passing an Array to a procedure, assuming you are not doing a ByVal pass?
You've provided a good bit of detail, but it's still quite difficult to understand exactly what's going on without seeing some code. In your question, I can identify at least 4 big topics that you interweave throughout: Manufacturing, Data Access, VBA, and Coding Best-Practices. It's hard for me to tell exactly what you're asking because your question scope is huge. Either way, I appreciate your trying to write better code in VBA.
It's hard for me to understand exactly what you plan to do with the arrays. You say:
The downside is that I am using much of the same base information in multiple procedures, which requires me to load it into arrays with minor differences multiple times.
I'm not sure what you mean here. Are you using arrays to represent a row of data that you retrieved from a database? If so, you might consider using class modules instead of the usual "macro" modules. These will allow you to work with full-blown objects instead of arrays of values (or references, as the case may be). Classes take more work to set up and consume, but they make your code a lot easier to work with and will greatly help you to segment your code.
As user Emtucifor already pointed out, there may be objects such as ADO Recordset objects (which may require Access to be installed...not sure) that can help greatly. Or you might create your own.
Here's a long example of how using a class might help you. Although this example is lengthy, it will show you how a few principles of object-oriented programming can really help you clean up your code.
In the VBA editor, go to Insert > Class Module. In the Properties window (bottom left of the screen by default), change the name of the module to WorkLogItem. Add the following code to the class:
Option Explicit
Private pTaskID As Long
Private pPersonName As String
Private pHoursWorked As Double
Public Property Get TaskID() As Long
TaskID = pTaskID
End Property
Public Property Let TaskID(lTaskID As Long)
pTaskID = lTaskID
End Property
Public Property Get PersonName() As String
PersonName = pPersonName
End Property
Public Property Let PersonName(lPersonName As String)
pPersonName = lPersonName
End Property
Public Property Get HoursWorked() As Double
HoursWorked = pHoursWorked
End Property
Public Property Let HoursWorked(lHoursWorked As Double)
pHoursWorked = lHoursWorked
End Property
The above code will give us a strongly-typed object that's specific to the data with which we're working. When you use multi-dimension arrays to store your data, your code resembles this: arr(1,1) is the ID, arr(1,2) is the PersonName, and arr(1,3) is the HoursWorked. Using that syntax, it's hard to know what is what. Let's assume you still load your objects into an array, but instead use the WorkLogItem that we created above. This name, you would be able to do arr(1).PersonName to get the person's name. That makes your code much easier to read.
Let's keep moving with this example. Instead of storing the objects in array, we'll try using a collection.
Next, add a new class module and call it ProcessWorkLog. Put the following code in there:
Option Explicit
Private pWorkLogItems As Collection
Public Property Get WorkLogItems() As Collection
Set WorkLogItems = pWorkLogItems
End Property
Public Property Set WorkLogItems(lWorkLogItem As Collection)
Set pWorkLogItems = lWorkLogItem
End Property
Function GetHoursWorked(strPersonName As String) As Double
On Error GoTo Handle_Errors
Dim wli As WorkLogItem
Dim doubleTotal As Double
doubleTotal = 0
For Each wli In WorkLogItems
If strPersonName = wli.PersonName Then
doubleTotal = doubleTotal + wli.HoursWorked
End If
Next wli
Exit_Here:
GetHoursWorked = doubleTotal
Exit Function
Handle_Errors:
'You will probably want to catch the error that will '
'occur if WorkLogItems has not been set '
Resume Exit_Here
End Function
The above class is going to be used to "do something" with a colleciton of WorkLogItem. Initially, we just set it up to count the total number of hours worked. Let's test the code we wrote. Create a new Module (not a class module this time; just a "regular" module). Paste the following code in the module:
Option Explicit
Function PopulateArray() As Collection
Dim clnWlis As Collection
Dim wli As WorkLogItem
'Put some data in the collection'
Set clnWlis = New Collection
Set wli = New WorkLogItem
wli.TaskID = 1
wli.PersonName = "Fred"
wli.HoursWorked = 4.5
clnWlis.Add wli
Set wli = New WorkLogItem
wli.TaskID = 2
wli.PersonName = "Sally"
wli.HoursWorked = 3
clnWlis.Add wli
Set wli = New WorkLogItem
wli.TaskID = 3
wli.PersonName = "Fred"
wli.HoursWorked = 2.5
clnWlis.Add wli
Set PopulateArray = clnWlis
End Function
Sub TestGetHoursWorked()
Dim pwl As ProcessWorkLog
Dim arrWli() As WorkLogItem
Set pwl = New ProcessWorkLog
Set pwl.WorkLogItems = PopulateArray()
Debug.Print pwl.GetHoursWorked("Fred")
End Sub
In the above code, PopulateArray() simply creates a collection of WorkLogItem. In your real code, you might create class to parse your Excel sheets or your data objects to fill a collection or an array.
The TestGetHoursWorked() code simply demonstrates how the classes were used. You notice that ProcessWorkLog is instantiated as an object. After it is instantiated, a collection of WorkLogItem becomes part of the pwl object. You notice this in the line Set pwl.WorkLogItems = PopulateArray(). Next, we simply call the function we wrote which acts upon the collection WorkLogItems.
Why is this helpful?
Let's suppose your data changes and you want to add a new method. Suppose your WorkLogItem now includes a field for HoursOnBreak and you want to add a new method to calculate that.
All you need to do is add a property to WorkLogItem like so:
Private pHoursOnBreak As Double
Public Property Get HoursOnBreak() As Double
HoursOnBreak = pHoursOnBreak
End Property
Public Property Let HoursOnBreak(lHoursOnBreak As Double)
pHoursOnBreak = lHoursOnBreak
End Property
Of course, you'll need to change your method for populating your collection (the sample method I used was PopulateArray(), but you probably should have a separate class just for this). Then you just add your new method to your ProcessWorkLog class:
Function GetHoursOnBreak(strPersonName As String) As Double
'Code to get hours on break
End Function
Now, if we wanted to update our TestGetHoursWorked() method to return result of GetHoursOnBreak, all we would have to do as add the following line:
Debug.Print pwl.GetHoursOnBreak("Fred")
If you passed in an array of values that represented your data, you would have to find every place in your code where you used the arrays and then update it accordingly. If you use classes (and their instantiated objects) instead, you can much more easily update your code to work with changes. Also, when you allow the class to be consumed in multiple ways (perhaps one function needs only 4 of the objects properties while another function will need 6), they can still reference the same object. This keeps you from having multiple arrays for different types of functions.
For further reading, I would highly recommend getting a copy of VBA Developer's Handbook, 2nd edition. The book is full of great examples and best practices and tons of sample code. If you're investing a lot of time into VBA for a serious project, it's well worth your time to look into this book.
It sounds like maybe Excel and arrays are not the best tools for the job you're doing. If you could please explain a little bit about the type of data that you're working with and what you're doing, that will really help provide a better answer. Give as much detail as you can about the types of manipulations you're doing on the data and what the inputs and outputs are.
I'm going to give some highlights that I think will help you, and then may edit my answer to be more complete as I get responses from you, and so I have more time to flesh things out a bit.
There is an object that naturally handles the record-type objects you're working with called a Recordset. In the VBA editor, go to Tools -> References and add Microsoft ActiveX Data Objects 2.X Library (the highest one on your machine). You can declare an object of type ADODB.Recordset, then do Recordset.Fields.Append to add fields to it, then .Open it and finally .AddNew, set field values, and .Update. This is a natural object to pass around in programs as an input or output parameter. It has natural traversal and positioning functions (.Eof, .Bof, .AbsolutePosition, .MoveNext, .MoveFirst, .MovePrevious) and supports searching and filtering (.Filter = "Field = 'abc'", .Find and so on).
I don't recommend using public variables, though without an understanding of what you're doing I can't really advise you well here.
I also would avoid one big procedure. Code should be broken out into reusable functional units that do only one thing, whose names are essentially self-documenting about what they do.
If you want to improve the performance of your code, hit ctrl-break at random times while it's running and break into the code. Then press Ctrl-L to view the call stack. Make a note of what is in the list each time. If any item shows up a majority of the time, it is the bottleneck and is where you should spend your time trying to optimize it. However, I don't advise trying to optimize what you have until you make some higher-level decisions (like whether you will switch to a recordset).
I really need more information to help you better.
If you're interested, I'll work up some demonstration code that will show how useful the Recordset object is. Inserting the data from a Recordset into an Excel range is super easy with Recordset.GetRows or .GetString (though some array transposition may be required, that's not hard, either).
UPDATE: If your goal is to speed up your process, then before doing anything I think it's best to be armed with the knowledge of what is taking the most time. Would you please hit ctrl-break about 10 times and note down the call stack each time, then tell me what the most common items in the call stack are?
In terms of updating the speed of cell formatting, here's my experience:
Merge is the slowest operation you can possibly do. Try to avoid it if at all possible. Using "center across selection" is one alternative. Another is just not merging, but using some combination of sizing properly, borders, cell background color, and turning off gridlines for the entire workbook.
Apply borders or other formatting once to the largest thing possible instead of to many small things such as cell by cell. For example, if most cells have all borders but some don't, then apply all borders to the entire range and during your looping remove the ones you don't want. And even then, try to do entire rows and larger ranges.
Save a template file with borders and formatting already applied. Let's say you put one row in it with the formatting for a certain section. In one step duplicate that row into as many rows are needed for that section, say 20 rows, and they will all have the same formatting. Duplicating rows is MUCH faster than applying formatting cell by cell.
Also, I wouldn't automatically go for using classes. While OO is great and I do it myself (heck, I just built 8 classes for something the other day to model a hierarchical structure so I could easily expose the parts of it when I needed them), in practice it can be slower. A simple set of public variables in a class is faster than using getters and setters. A user defined Type is even faster than a class, but you can run into gotchas trying to pass around UDTs in classes (they have to be declared in a non-class public module and even then they can give problems).