If Statement Or Where Extension With A For Each Loop?
Nov 18, 2009I was wondering which of the two code samples would be more efficient (or is the difference between the two negligible)?[code]
View 4 RepliesI was wondering which of the two code samples would be more efficient (or is the difference between the two negligible)?[code]
View 4 Repliesy friend and I are re-learning Visual Basic, and we are stumped on this bit of code.
For intAsterisks As Integer = 0 To intLine - 1
lblAsterisks.Text = lblAsterisks.Text + "*"
Next
I am trying to understand how a for each loop works and am having some trouble. I am trying to create a program that will query a sql database, pull back the information and store it. I currently having it writing to a text file, and would like to take the information (such as name) and compare it to another list where the name is equal. However I am not exactly sure how the for each statement really works. I have looked at numerous sources and it doesn't make since to me as you can probably see from what I have put in here.
HTML
Public Class Form1
Public Sub newarrest()
Dim strsports As New System.Collections.Generic.List(Of String)
Dim employeelastname As New System.Collections.Generic.List(Of String)
Dim cnPodaci1 As New SqlConnection
[Code] .....
I am a new with using datarowview
The problem here is how to loop in dataRowview using for statement
I'm practising printing, and doing fairly well - not as hard as I was thinking.
My question is: is it better/preferable to use a "while..." loop instead of an "If..then" statement when printing.
All my printing code is in various If statements (if PgNbr = 2, If PgNbr = 3 etc) but I notice in most of the examples and webpages I read that a lot of printing is done in a "while..." loop
For loop statement with .count method
View 1 RepliesIf completedOrders.Count <> 0 Then
For i = 0 To completedOrders.Count - 1
SyncLock completedOrders
'Do some work, for example this:
Dim text As String = completedOrders(0).getCN & " " & completedOrders(0).getDeviceName & " "
End SyncLock
Next
End If
Is a synclock needed before the if statement or for loop? In other words. When you call methods like .length or .count is it necessary to synclock them or can another thread be writing to it at the same time. CompletedOrders is a generic list of a class.
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim s As New Staff
[Code]....
Basically I am trying to update each record with 2 random numbers each time the button was clicked,my problem now is, the system will update the record but the data was wrong. Example, by right all data should be different (randomly string) but for some row it was updated with same data but in randomly, something row1 row2 row3 has exactly same data for column 1 and 2 then row 3 has distinct data, second time, row1 row2 same data row3 ro4 with different data. It is in random sequence. When I add a MsgBox to do testing in the For loop the data was updated correctly with all different data.
i have 10 radio buttons that have yes/no values. These are options to one question, so need to in the database under 1 record. so - question1 yes, question 1 no, question1 yes and so on. i want to use a while loop or some other loop to take all these values and insert them or update them in the database for that particular question. i m new to programming. the db table is ID, question, Answer. so it will be 1 question1 yes, 2 question1 yes, 3 question1 no.
View 2 RepliesI would like to terminate a do until ....loop when future value is greater than 1000 without using a Exit or Continue statement.
Do Until inti > intMonths
decFutureValue = (decFutureValue + decMonthlyInvestment) * (1 + decMonthlyInterestRate)
If decFutureValue > 1000 Then
[code]....
I am having a few issues with a For loop statement, code below:
Dim y1 as integer = "12"
Dim y2 as integer = "24"
Dim y2a as integer
[Code]....
Problem i have is that it selects all records that have a value equal to or less than 24 rather than the records that have a value greater than 12 and equal or less than 24. This appears to be an error i am making in the use of greater and less than?
I am currently teaching myself the caveman code of Visual Basic (VB.net). Apparently I fail at If-statements or something, because I cannot get this to work...
[Code]...
Is it possible to define my list of strings like in 'good old' VB60, to use only on ebyte of memory for each character? .NET always seems to store any string as unicode, which doubles the required memory. The case is that I have a huge list of strings, all of the same size. It is about 50.000.000 items, 12 characters each. You can imagine I am running out of memory in no time. I tried converting them to arrays-of-bytes but in that case I loose the possibility to perform a "LIKE" statement in a FOR-EACH loop to check for a specific item.
View 6 Repliesif I have the following vb code,
for i = 0 to dTable.Rows(i).Count -1
Dim sql As String = ""
Dim strConn As String = ConnString
[Code]....
[code] The problem in my case, this is not working with this code. All I need are random numbers outside the above boundaries.Please note when I remove 'Not' in 'Loop While' statement, the programme runs indefinitely!!
View 11 RepliesI am trying to create a program in vbfor this problem: "A TV set is purchased with a loan of $563 to be paid off with 5 monthly payments of $116. The interest rate is 1 percent month. Display a table giving the balance on the loan at the end of each month". It must have 1 button and a list box that displays successive balances, contains loops to balances, loop code includes output to the list box, List box displays 2 columns (one for month and one for amount owed) and 5 months are displayed and the amount owed for each. The Amount Owed should go down each month from month 1 to month 5 where month 5 will equal to $0.00
Here is my code so far but somehow the 1 percent interest i cannot get to add on each month so I am not getting the write answer.
Code:
Dim rate As Decimal
Dim loan As Double
Dim pay As Double
[CODE]...
I have attached a jpeg of what the end result should look like when code is being run.
I'm trying to create a "quiz" program in VB. The questions to be asked are placed inside text files and have the following format:
[code]...
> VB thinks that im trying to open a file named, what im trying to do is open a txt file which have a file name similar to the value of integer.
labelQuestion.text = variable.Readline().
I am having problem with the coding of this (endless loop) and formatting of summary boxes before tests are complete that should not happen. (the overall goals is to have a separate validation procedure that does not calculate or dat displays are not performed until after call function is complete and valid. The validation that takes place are that two boxes are filled in - one is text and the other is a numeric value. (using vb 2008)
[Code]...
Why would I use an extension method instead of just creating non-extension sub or function?
For ex, I could have an extension function called IsNullOrEmptyOrAllSpaces on String, which does a check as its name implies. Or I can write a stand alone function that does the same thing. Other than having the extension show up in Intellisense, is there any advantage? Is a call to the extension quicker/more efficient than a call to a regular function?
I saw this post and I want to know if this is possible in VB. So like extension method, do extension properties exists in VB.Net? Here I've read they do, but cannot find any examples.
View 3 RepliesIf i have an extension ... say...
vb
<System.Runtime.CompilerServices.Extension()> _
Public Sub Invert(ByVal b As Bitmap)
is there any way of hiding this from inteli-sense if it is not used as an extension?so that pressing ctl+space only triggers it if you go "bitmap.Inve.." rather than prompting on "Inve..."?
Makes the following statement about the code below:
**"The computer evaluates the loop condition in the Do...Loop statment to determine whether the loop instructions should be processed. In this case, the inputsales <> String.Empty condition compares the contenst of the input sales variable to the String.Empty value. As you know the String.Empty value represents a zero length, or empty, string if the inputsales variable is empty, the loop condition evaluates to True and the computer process the loop instructions. *If on the other hand the inputsales variable is not empty, the loop condition evaluates to false and the computer skips over the loop instructions.
Based on the code I think it is the opposite: ...that while the inputsales value is not empty it should evaluate to true and process the loop and if it is empty it should evaluate to false and skip the loop?
See below.
Option Explicit On
Option Strict On
Imports System.Globalization
[CODE]...
I am using VB 08 running an openfiledialogue wanting to get the result of the GDS file (*.gds) to be the default extension at the drop down menu instead of All file when the openfiledialogue box opens.
I coded it with:
OpenFileDialogue.Filter = "GDS File(*.gds)|*.gds|All files|*.*"
but the results i get in the open file dialogue box remains as all files being in the drop down menu as the default file extension. How to i set it to ".gds" format?
See
Public Class Form1
Dim sql As String
Dim conn As New OleDb.OleDbConnection
Dim da As New OleDb.OleDbDataAdapter
[CODE]...
The problem, The INSERT statement works fine in the form load but not in the button click event?
I was convinced that If <expression> Then <statement [:statement]> Else [statements] in concrete form of If a = b Then SayHello() Else SayBye() End has sense. I read article on msdn on If-then-else, but I forgot why I was reading, so I concluded, that snippet above means this
If a = b Then HelloIsSaid : IsNotEnded Else ByeIsSaid : IsEnded But I have tested it now, and I see, that Else without statement is nothing more than decoration. It would be pretty good if it had function I described. Do you think its good request? Or do you know any circumstance where this Else has some function?
I have the following SQL:
[Code]...
I want to put it (the select count statement) in this LINQ statement so I can get the sales count in my linq statement: Dim TheLeads = (From L In DB.Leads Where L.IsDeleted = False Select L).ToList() Is this possible to do in LINQ?
add an if statement and an exit statement to my do loop that exits when my future value (FV) is greater than 1000, then to change the exit statement to a continue statement so my loop will continue even though my fv is greater then 1000, point is to get this to run even though my if statement doesnt do anything. problem something wrong in my code and an exception error (xception of type 'System.OverflowException' occurred in mscorlib.dll)
so can someone show me where or why I have an error is, what am I overthinking now! I could use a hint, OMG i could use a tutor for that matter
[Code]...
A co-worker wants to convert the following IfThenElseIf statement into a Select Case statement.
Explain why this is not possible.
If temperature = 100 Then
X = 0
ElseIf population > 1000 Then
X = 1
ElseIf rate < .1 Then
X = -1
End If
I cant get this SQL statement to insert any of the values in the form to add to the database
sql
sql = "INSERT INTO prevresults (ExamDate, ExamTime, CorrectAnswers, PassPercentage) VALUES (date.now, time.now, rightanswers, percentage.text)"
[code]....
I am attempting to loop through an array of some sort (doesn't really matter) and evaluate it in an If statement. If I put the "If...Then" immediately after the "For Each..." declaration it only checks the first item and then will jump out of the For loops. However if I pass the item to a variable and then evaluate the variable, it works fine.
Case in point:
For Each pool In nodeList
For Each node In pool
If node = host Then
[code]....
does not work, yet:
For Each pool In nodeList
Dim pool2 = pool
For Each node In pool2
[code]....