Class With Dynamic Arrays Inside Another Class Which Also Has Dynamic Arrays?
Nov 15, 2011
Below you will find a code sample that I have dummied up to try and demonstrate the issue I am having. However, this is just a dummied up piece of code. The actual program has noting to do with STUDENTS or TEACHERS. Basically, the problem I'm having is trying to have a CLASS within another CLASS each of which contain ARRAYS that need to be dynamic in size. The sample has a CLASS called STUDENTS that can have in theory many students, the number of which are unknown to the CLASS. I need to be able to add STUDENTS to the ARRAY programmatically.
The CLASSROOM Class should also be an Array since each TEACHER will have MANY Students. There will be only 1 Teacher for a given classroom but the SCHOOL will have MANY CLASSROOMS. Again, I need to programmatically add Teachers and Students without having predefined Array sizes. The code I have listed below will NOT work but it demonstrates what I am trying to achieve. I want to be able to reference the CLASS by using something like this ...
I feel like I should be able to use ARRAYLIST in both classes but haven't been able to get it to work. I've tried DIM'ing as ARRAY and can't get that to work either.If I can get ARRAYLIST to work then I shouldn't need to worry about expanding the array via UBOUND (if it's even possible).The REAL question is "How do I have a CLASS within a CLASS, each of which has ARRAYS that need to be dynamic in nature so they can be expanded as needed? The size of the array cannot be determined ahead of time".
REMEMBER . . . the actual program has nothing to do with Students and Teachers. This was just my way of demonstrating the issue using an analogy that I thought everyone could understand. The actual Class is much more involved.I have purposely hardcoded some values just to make the sample easier to work with. This is NOT how I normally program but is just here to hopefully make things a little more clear.
Here is the sample code . . .
'***********************************************************************************
'***********************************************************************************
'***********************************************************************************
'Here is the code that is in the form - This obviously doesn't work
Private Sub TeacherTestDemo()
Dim iTeacherIndex As Byte
Dim iStudentIndex As Byte
I'm trying to create a dynamic jagged array. That is, one that i can increase the size of at runtime. Maybe its easier if I show you. I have a folder containing a varied number of files. What I want to do is set up a jagged array, with the file contents as the second array. So kind of like this:
However, it throws a System.NullReferenceExeption when I try that. In addition, I don't understand jagged arrays all that well....Here is my code (that doesn't work). The jagged array must be accessible by other methods.
A project requires to allocate a varying number of byte arrays (buffers).
It would be ideal if the following definition would be possible:
Dim ArrayOfBuffers() as buffer(10000) as Byte
The byte arrays must be ordered sequentially because they have to be written to a file by efficient procedures destinationFile.Write(ArrayOfBuffer(3),1000,1000)
The number of buffers will change during program execution sometimes. Therefore it would be nice to be able to do a ReDim on the data structure when needed.
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Here I declared the arrays: Public Class Form1 Private occupied() As Integer Private plyrTaken(8) As Boolean Private plyrPairs(14) As Boolean
Here I got the dynamic array ready for use: Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load ReDim occupied(0)
And here is the code I have attempted: For index As Integer = 0 To 8 If plyrTaken(index) = False And cmptrTaken(index) = False Then ReDim Preserve occupied(UBound(occupied) + 1) [Code] .....
In the last block of code I was just trying to print the contents of the array to a list box so I could see if it was working. Obviously, it's not. When one position is occupied the list box shows the occupied cell index with a Zero. This really shouldn't be there as I want only taken cell indexes to be sent to array and list box. When a second position is occupied 7 zeros are added to the list box. Kinda shows promise as 9 total cells - 2 is 7 but there should be index numbers other than zero to represent the cells that have been occupied.
Also, the indexes shouldn't keep adding on to the dynamic array I need a way to clear the array and resize it back to 0. I tried adding Redim occupied(0) to the top of the code but that didn't seem to work.
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{{"aap", 1}, {"noot", 2}, {"mies", 3, "boom"}, {"vuur", 4, 7}} now i tried to declare
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Namespace TestDesign Public Class HomePage Inherits IE
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I believe I must be approaching this incorrectly and though I can find dozens of examples of setting class variables and even a couple on using arrays as class variable, I can not find any that show how to then pass values to those arrays.
Public Class Statement Private _tranDate(1) As Date Private _amount(1) As Double
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Public Class Form1 Public k() As Integer Private Class zaratma
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'Created/ Revised by: Jessica Falcetta 'Cap 204 Final Project: Big Integer Project 'Project Purpose: To calculate large integers through parallel arrays
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the statement Dim state(49) As String and maintain a list of certain states. The list of states should always be in alphabetical order and occupy consecutive elements of the array. The buttons in the program should give the user the following options: (a) Take the state specified by the user in a text box and insert it into its proper position in the array. If the state is already in the array, so report. (b) Take the state specified by the user in a text box and delete it from the array. If the state is not in the array, so report. (c) Display the states in the array. "
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