I have about 100 strings that depend on an integer value. There is potential for the list to grow to 255. What is the faster/preferred method of assigning the string based on the passed integer, a hash table or a switch statement. I googled around and can't seem to find anything that compares the speed of the hash table lookup vs. the speed of the switch statement. Is there an easy way I could measure the speed myself or any links to articles describing the performace of each method?
I have a page with a URL that includes a hash value (www.mysite.com/#123).What I want to do is use that value to determine what is displayed on the page - much like using a querystring.I am using the hash value because the content on the page can be changed client side (I am avoiding page reloads where possible) - if the user then links to another page and uses the back button to return, I need to use the hash value to display the page as it was when they left it.So I'm looking for an if statement that will look something like this:
I was reading an interesting article here and it made an interesting point about the 'case' statement in vb.net vs the 'switch' statement in C#, which I've pasted below:The following Visual Basic Select Case statement can't be represented in C# with a single switch statement:
Dim Condition As Integer = 55 Select Case Condition Case 1, 3 To 5, 10, 12, 14, Is > 50
[code]....
I've always found the switch statement in C#, with dropthrough and consequentrequirements for a break in each case, to be a bit unwieldy. Is there any reason they haven't enhanced the switch command to allow these situations? W
EDIT AFTER CLOSE: I'm surprised this was closed, really. With the number of extension methods and helper classes I've found online for other things, I thought an enhanced 'case' would be a good chance. I somewhat hoped a luminary such as Jon Skeet may have commented on the background reasoning, rather than the individuals below who've obviously thought 'religious debate' as soon as more than one language is mentioned.
I am not really a fan of if statements. I think they should only be used when comparing different values like this:
Dim status as boolean = false Dim number as integer = 5 if status.equals(true) then
[Code]....
or msgbox on a different line whatever you want.... What is this rule about that select case should only be used if there more then 2-3 options. Is it wrong to use a select case instead?
Dim executeB As Boolean Select Case myVariable Case "a" 'some code Case "b" 'some code Case Else End Select
If myVariable is "a", control will go into the first case statement. Now let's say if myVariable = "a", but inside a's case block, I find that executeB is true, is it then possible to jump to the second case?
[code]How would I switch on an object's type but using VB.NET's Select Case?I'm aware that some might suggest using polymorphism but I'm using a hierarchy of small message classes so that really wouldn't work in my csae.
I was asked by an employer to sort a hash table. I always thought that the usage of a hash table was in a way non-sort friendly. Am I wrong in thinking this, and if not can you point me to a good VB.Net(Yes Kill me now, but it's an old system) method of sorting a hash table.
Currently I add data to a hash table, then later on I loop through the hash table. To my horror I discovered that when you use FOR EACH with a hash table it doesn't return the items in the order you added them.I'm looking for a collection that I can add, edit and delete items from and loop through from start to end in that order.
i need to create a hash table using a multiplication method and i need to create an array of linked listso how i can to create array of linkedlist in vb or c# ?
I have a register.aspx and a login function and i am using vb.net
in my register.aspx...i have a user name textbox and a password text and a submit button. IF the user click on the submit button, the password will be hash and store with the username in the database table called "Customer"
1st Qn: i have a problem is that i never try before hashing, so i not sure how to code it , hopefully if someone got a sample or example to teach me it will be nice
2nd Qn: besides that, in my login function, how am i going to compare the hash value for password that is store in database with the password in the textbox to allow to login?
I am interested in the pros and cons of data tables and arrays in VB 2010. I programmed decades ago in FORTRAN and used arrays extensively.However, I frequently see data tables in code snippets and don't know when they should be used in lieu of an array.
just want to know what is the difference between these date values?Once some one told me that its difference is server date and client date but not sure which one he meant.Below is 3 type of date currently I'm using and don't know what is the difference between them.
DateTime.Now is from System.DateTime.Now Now is from Microsoft.VisualBasic.DateAndTime Today.date is also from System.DateTime
What is the best way to compare an Int entry from a table in a case statement?Using SQL server 2008 R2, Visual Basic Express with LINQ to SQL.The code I tried doesnt work:
Private Sub UpdateSetOpt() Dim db = New ACEDataContext Dim SRM = From q In db.Settings
my program is "live" and my customer has troubles because it doesn't functioning as well as it should.I don't know what happen, did I changed something or not but suddenly data won't save to database from newly created forms. Beside this form I have additional 20 forms and everything is working like a charm and I use same code logic to save data to database. I tried to find myself what could be the reason, check by entering data directly to database table (works fine), check insert statement of dataset table (seems fine, too) and everything I could imagine. But now I ran out of ideas and I had to ask here.
Also, I added 3 fields to database table (nvarchar, int and decimal). All 3 of them allow nulls. I changed dataset and data entry form and now data won't insert if I dont enter values to int and decimal fields. Also, this decimal field doesn't accept 0 value if enter but if I assign value 0 from the code than it is ok. I'm not sure if I somehow changed concurrency and somewhere. I tried to find where I can change it but I couldn't find it. I use Visual Studio 2008 and Sql Server 2005 Express. Language vb.net.
I am trying to input specific information on a form.I have created an sql statement from a table that will out put 18 rows of data.I have opened a recordset and instituted a do until loop.I need for the program to look at each row and if the Standard Score = the value of a field I have on the form it takes the value of the other three columns in updates it on the form.I have created the code and it works for upto 3 (Do Until loops)records, but when I try to add a 4th in the SQL statement and put in another do loop my computer runs it but it acts as if it freezes up. [code]
I am trying to insert into a DB with has the following columns: ID (autonumber), BonderIdentifier (text), Username (text), Login (date), Logout (date). BonderIdentifier, Username, Login is the PK.
Here is what I do: Public Function submitNewToDB(ByVal sessionData As BonderSession) As Boolean Dim cn As OleDbConnection Dim cmd As OleDbCommand Dim str As String [Code] .....
Like I said I get an insert into error and I dont know why. Nothing is in the DB yet and the table is created. I ran the built string in Access as such: Insert into Session ([BonderIdentifier], [Username], [Login]) values ('Mork', 'sean', '2/23/2010 11:12:42 AM') And it works.... but in VS it doesn't.
I have three tables set up in a MySQL database called "event", "status" and "user". (as shown below:
EVENT TABLE (below) STATUS TABLE (below) USER TABLE (below)
and when I get data from the event table I use the SQL query statement below to bind the persons first and last names together as one variable called "name" and then bind that name to the respective user_id; and so on. However when I make changes to the event table it doesn't show the changes I've made. I'm certain it has something to do with the way I'm retrieving the data.
SELECT CONCAT(u.lastname, ', ', u.firstname) AS Name , s.message AS Message , DATE_FORMAT(e.timestamp,'%b %d %Y - %r') AS DateTime[code].....
Attempting to run an SQL statement to UPDATE a column in a table with new data. The column being updated is defined as varchar(40) and the new data is 41 bytes (varchar(41)). I get a generic 'data will be truncated' error message, but no detail on which column caused the problem. I've attached a sample VB program to illustrate the issue. In this scenario, Company is defined as varchar(40).
My question: Can I get a more detailed error message? i.e. can I get an error message that tells me the row and column that the truncation occurs in? Often times, I may be updating hundreds or thousands of rows and only one value in one column from the source file is too large for a database cell. As a related question, does each OLEDB provider create its own error messages. i.e. will the MS SQL Server OLEDB provider potentially give different text in the error message than say the MS Jet OLEDB provider?
Imports System.Data.OleDb Module Module1 Dim cn As OleDbConnection
I got a table related to another table by orderref. I need to know what should be my SQL adapter command if I need to take some information from one table and some from another where orderref = "" or should I be making two separate SQLs?
I used to have this when I had only one table: myStr = "select * from orders where Orderref='" + txtorderref.Text + "'" Dim sqldaHistory As New SqlDataAdapter(myStr, nwindconn) sqldaHistory.Fill(myDataset, "orders")
i am using vb/vb.net and the database is visual foxpro 6.0 then i want to create the tables from the application using sql statement.i need to add the number field into the table. i can not add the number field in the tableres.open "CREATE TABLE Customer ( CustName char(50), CustId int(2))",conXavier
In my programming task I've gone down a dark alley and wished I hadn't, but there is no turning back now.
I'm building up a SQL statement where the table name, column name and id value are retrieved from query string parameters i.e. ("SELECT [{0}] FROM [{1}] WHERE [Id] = {2};", c, t, id)
But it isn't as bad as it looks, I'm protected: Only authenticated users (i.e. signed in users) can execute the Page_Load I'm checking that both the table and the column exists beforehand (using GetSchema etc.)I'm checking that the Id is an integer beforehand All my tables have Id columns The database connection is reasonably secure
I have a IF statement which is checking each row in the data table (for a match) and ELSE statement with commands which are executed if the If statement is not satisfied. Now I would like to write like so that it goes to the Else part BUT ONLY for values which are not satisfied in the IF statement. If I am more specific; I would like to calculate values if a match is found and just print them if it is not fond (usually there are both cases). Now the problem is the bold text; if there is a match found I don't want it processed BUT if the match is found I do. How can I write that?
currencyPosition = 0 Dim d As Integer = w + 100 For Each currency In Ary