I have a custom class Y which includes a public property X as list(of string) which won't always have data
In my code I am trying to do the following dim x as list(of string) = Y.X if not x.count=0 then do somthing
The problem is that when Y.X has never been set, it causes an error. What would the proper way to check for Y.X be? I haven't really worked with lists too much.
I would like to test if ListBox1 is empty then test again until ListBox1 is NOT empty If ListBox1 is NOT empty then msgBox �You did it� and start over again, until i click a stop button
The problem is that when I start my program the listBox is ALWAYS empty and after 1-4 sec data will arrive in listBox1, but my loop (for testing if listBox1 is empty) is freezing up the application, because it�s always true and just looping infinity
I'm working on a program to delete files from a certain folder after they have aged a certain amount of time and either match via regex or extension. I'm running into an issue where files() could be: files(0) = Nothing files(1) = Nothing files(2) = Nothing etc....
Right now the way it is written, I could place Else log(1) = data(1) log(3) = "Array field empty" InsertLog(log)
And the program would log as many files as file(i) = Nothing holds. This would create redundant database records and is not wanted. Is there a way to figure out if ALL files(i) = Nothing and then place code in there to insert into the database?
'If log(3) is successful that means no files were old enough or deleted successfully If log(3) = "Success" And IsArray(files) Then For Each file In files If Not file.IsNullOrEmpty(file) Then 'If files is actually something insert into the log log(1) = file [Code] .....
On a button click I need to test whether or not an array has been filled, if it has the user gets linked to a new form otherwise they receive a message box telling them to first assign values to the array.
I've tried 'If MyArray Is Nothing Then....' and 'If MyArray.Length < 1 Then...' but neither seemed to have worked.
find the first empty value on an array?Say I have a directory and will occasionally be adding and removing items from an array to represent this. How would I go about making a loop until the entry is empty. I've tried various things like if null and that sort of thing but none of them seem to work- the problem is I guess that this array value is empty and the system can't deal with it without throwing an error message.Creating an array of a set size from the start isn't an option as I've no idea how big the directory will ultimately be.
Lets say I declare a public array for a structure, and initially I give it 99 indexes (well 100 with base 0), how would I get the first empty index? I thought of doing it like this but a structure array cannot be nothing:
Dim index As Integer Dim RecipeItem As New RecipeItem RecipeItem.name = InventoryList.SelectedIndex RecipeItem.amount = AddItemAmount.Value For index = 0 To _recipe_item.GetUpperBound(0)
What is the best way to take an array in VB.NET which can either be Nothing or initialised and give it a length of zero?The three options I can think of are:
ReDim oBytes(-1) oBytes = New Byte(-1) {} oBytes = New Byte() {}
The first example is what most of the developers in my company (we used to do VB 6) have always used.
I need assistance with posting lines from a text file (test scores) into an array. From there, I'll have to average the test scores, find the standard deviation (without using the built in function) and assign grades based on the test scores' deviation. I have already written the code for the user to search and upload a text file. And I should be able to do the standard deviation of the array, if someone can help give me an example of how to send the text file to array and average the lines of the array without using the built in math functions.
I've created a program that requires students to answer addition questions.I have the code so that it calculates if the answer is correct, along with outputing the correct answer into a textbox.If the answer is correct the textbox background colour changes to green.If the answer is inocrrect the textbox background colour changes to red.I've done this using an array, and I want to use this array to calculate how many questions the students have answered correctly, and output them onto another page.I'm not sure is something like this would work:I was thinking about giving the textbox that outputs the grade score a value of 10. For every red box that is highlighted, 1 is taken away from the texbox value, outputting the amount of questions the user has answered correctly.Here is my array so far, not including the ability to output how many answers the student has answered correctly.
Public Num1(10), Num2(10) As Integer Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
I have to write a program for a user to take a 20 question test (A, B, C, D). The users answers will be stored in an array and compared with a 2nd array that has the correct answers. Its then supposed to go to a 2nd form when you click show score, grade it, and display whether each answer was right or wrong. I'm missing something easy probably.
i noticed a problem with a program i made that occurs when an array element is called to use but is empty under a certain condtion therefor throwing an exception. i tried to define that element after the array was initialized to give it a default to use, but its not workin for me?
How do you declare an array when the array is initially empty?? I am taking multiple measurements from a meter that I want to put into an array. How would I declare that?? Here is my code to accept the last measured value.
HTML Dim measResult as string For I as Integer = 1 to 4 measResult = objDevice.gpibRead(i, 30) ''30 is the buffer size Next
How can I set up measResult so it is an array that will hold all of the measurements from the meter?? I have tried Dim measResult() as string, Dim measResult() as String = objDevice.gpibRead(1, 30) but no luck.
My objective is to find the lowest test score in the array and display it in the associated label using a DoLoop. However, I don't think I was to use the ForNext stmt.Could I have used the DoLoop without the ForNext? ' displays the lowest test score stored in an array
Dim testScores() As Integer = {14, 82, 94, 77, 11, 95, 38, 62} Dim lowest As Integer = testScores(0) Do For subscript As Integer = 1 To testScores.Length - 1
I have an array set up to receive the names of forms when they open. The form name is sent as a Form not a String therefore when I run my code I cannot check for whether the field is empty in the normal way (ie. array(1) = "") as the "" are only usable with strings!
Dim Forms(24) As Form Dim i As Integer Dim Free As Integer = -1
[CODE]...
I only need a solution to do the same as array(1)="" but for windows forms.
I have a large one dimensional array that is called ArrayHold which is populated at runtime. I run a loop to scan through the array to find out which elements need to be removed based on a few parameters. This all works great, now I am left with two arrays. The original one and a new one which contains the locations of the elements to be removed.
Original Array: ("A")("B")("C")("D")("E")("F")("G")("H")
Second Array with index/count of elements that needs to be removed: ("0")("3")("5")("7")
End result should be preferably not in a new array but a "ReDim" of the original array:("B")("C")("E")("G")
What would be the simplest way to achieve this? I could run a loop to make all the elements that need to be removed "0" or ""? Would there be an easy way of resizing and array by dropping/removing all the white space or empty elements?
I'm basically trying to do a small report card project. I only need to pull 5 Students with each student having 5 Test Scores a piece. The full Code of what I have for the submit button is below. I have actually 3 questions.
1. I always seem to have trouble with them unless I initialize them when I dim them. Is there a better way than below
2. The below code works really well for Student 1 and all 5 test scores. Rather than do that code 5 times though, what is the best way for me to basically state that IF dblStudent1(intMax) = 4 Then Change dblStudent1(intMax) to dblStudent2(intMax) etc.
3. Would this be better suited towards a multidimensional array ?
Private Sub btnEnterGrades_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEnterGrades.Click
Dim strStudentNames() As String = {" ", " ", " ", " ", " "} ' Holds the 5 Students Names Dim intMax As Integer = (4) ' Place Holder for Student Number
I'm used to PHP where I can declare a multi-level array like $something[0][1] = "test";. I need to be able to accomplish the same thing, but I'm using VB.NET. How would I do this?
And sorry if this isn't what a multi-dimentional array is, I might be wrong at what it's called but that's what I want to do.
i have a string array that i want to output to a text file. the array size is 10000. i fill the array starting from 0 with some strings. at the end, i only want to show the array from index 256 to the last array that is not empty (for eg. if the array is filled with data from 0 to 2000, i only want the text file to show the data from 256 to 2000 and ignore the remaining strings). Is there any function to do this?t i use is shown below
Dim myArray(10000) as string Dim strArray As New System.IO.StreamWriter("c:List.txt") strArray.WriteLine("{0,10}{1,30}", "Index", "Symbol")
and from VB6 project I reference to Test.dll but an error messege was appear A reference to Test.dll file could not be added (If I create VB NET project and reference to file Test.dll it OK )
i have a string array that i want to output to a text file. the array size is 10000. i fill the array starting from 0 with some strings. at the end, i only want to show the array from index 256 to the last array that is not empty (for eg. if the array is filled with data from 0 to 2000, i only want the text file to show the data from 256 to 2000 and ignore the remaining strings). Is there any function to do this? i am using visual basic express 2008. The code that i use is shown below
Probably a dumb question, but can you write a unit test project in one language to test against another project in a different language?I'd like to translate one of our VB assemblies into C#, but want to build unit tests to verify the results. I've tried to set a unit test project up to do this, but I can't seem to access the VB code within a unit test... I can't figure out if I'm just missing/doing something stupid, or it really isn't allowed.
I have a DataGridView that has some columns with dates. It binds to an in-memory Datatable which gets loaded from an string array of data passed back from the backend Some of the rows returned have nulls for the date columns. Solution 1: If I define the Date column in the DataTable as "string" I can easily convert those nulls to empty strings and display it in the grid as empty strings (desired results). However, if the user clicks on the date column header to sort by date, it doesn't order the rows as you want. You get a purely string sort order. Not acceptable
This must've have been asked before but I couldn't locate it. In a mixed code project (VB and C#) we were debugging some old Visual Basic code where a statement as follows could be found:
If Request.Params("xxx") <> "" Then 'do something
I considered this a bug as Request.Params could be null, in which case the statement would've become false which wasn't the idea. So I thought. I just found out, -- probably for the tenth time and I will keep forgetting -- that the following two statements are not equal, while Nothing in VB should be equal to null in C# (thought I):
if(String.Empty == null) // always false If String.Empty = Nothing Then ' always true
Should I dismiss this as a typical Microsoft backward compatibility effort, or should I consider this a huge error in the VB.NET compiler? Does anybody know the Microsoftean opinion on this oddity?
I have an array of people stored in a custom structure array... how can i copy this array to a temp array so that the temp array has all the same values as the original custom array?
