is there any way to remove the element in char array I converted from a String?
Dim myString As String = "Hello"
Dim charArray As Char() = myString.ToCharArray
Your help would be much appreciated.. Thanks
Arrays are fixed-length in .NET. You can set an element to Nothing but you cannot remove that element. You can use a collection instead of an array and then you can add, insert and remove items at will, but your example isn't necessarily the best case for that sort of thing, e.g.
Dim str = "Hello"
Dim chars = New List(Of Char)(str)
You can then call Remove or RemoveAt on that List to remove a Char. You can then create a new String if desired, e.g.
chars.RemoveAt(2)
str = New String(chars.ToArray())
Console.WriteLine(str)
That will display "Helo".
Related
I have many strings that have numbers at the end. The numbers can be of any size, for example:
myvar123
mysecondvar3
mythirdvar219107
The strings can have numbers even inside the name, not only at the end.
for example:
my2varable123
some123variable9480395
I would need to replace any number at the END with a placeholder. (NOT those inside the varname.)
for example:
my2varable123 should become: my2variable%placeholder%
some123variable9480395 should become: some123variable%placeholder%
The only way that comes to my mind is to go through the string using .right() and remove the char if it is numeric until I find the first non numeric char. Then in the end append the placeholder, but it looks like a lot of work for a rather simply problem.
Is there a better way to do this?
You could use a Regex for this.
Dim str As String = "some123variable9480395"
Dim pattern As String = "\d+$"
Dim replacement As String = "%placeholder%"
Dim rgx As Regex = New Regex(pattern)
Dim result As String = rgx.Replace(str, replacement)
I have the data with the pattern of 8 char in my string. Those data are form from digits. Example: 00000001, 00004235, 081035670. Is that any methods in vb i can use to remove all the left padding zero from each of the strings?
You want String.TrimStart, it removes the leading character (you could also use an array and remove a set of characters).
Dim lines as List(Of String) = From {"00000001", "00004235", "081035670"}
For Each str as String in lines
Console.WriteLine(str.TrimStart("0"c)
Next
Just convert it to Integer and convert back to string
Dim data As String = "00000001"
data = Convert.ToInt32(data).ToString()
MessageBox.Show(data)
UPDATED:
String.TrimStart() is better solution (answered by jmoreno)
when I do
String.Join(";", lst.Items)
I get a string of object descriptors instead of item of values.
But when I iterate the collection, I end up with a delimiter at the front or back and need to a Substring call afterwards.
Dim res As String = "" 'or use stringbuilder
For Each s As String In lst.Items
s &= ";" & s
Next
res = res.Substring(1)
This applies to other cases as well where you want to turn a shared property within a collection into a delimited string. Is there a nice way to do this?
Can I do this with LINQ and would it be faster?
You'll have to convert the items to strings then:
String.Join(";", lst.Items.Select(Function(item) item.ToString()));
How about
Dim res As String = String.Join(";", lst.Items.OfType(Of String))
This does work:
Dim col As New Collection
col.Add("One")
col.Add("Two")
col.Add("Three")
Dim res = String.Join(";", col.OfType(Of String))
See also this question
I have a ComboBox which I assign to a variable:
Dim var as String = ComboBox1.SelectedValue
Dim name As String = var.Split(",")
This gives me the error
Value of type '1-dimensional array of string' cannot be converted to String
Any ideas as to where I'm going wrong?
Split returns an array of strings. Your variable needs to be changed to an array, not just a single string.
My VB is a bit rusty, but I think you have to make name an array:
Dim name() As String = var.Split(",")
name needs to be declared as an array.
dim name() as string = var.split(",")
The split() method will break up the string based on the given character and put each newly created string into an array and return it.
This is what your error message is telling you:
Value of type '1-dimensional array of string' cannot be converted to String
The method returns an array of string, but your trying to put it into just a string!
EDIT: In response to your answer...
So far you've managed to split the string yourself with the split method. To output this to your message box, you need to concatenate the two elements in the proper order:
msgbox(name(1) & " " & name(0))
Notice I indexed the array twice! Element 1 is the first name, element 0 is the last name. Remember you got this name in lname,fname format. Passing the array itself doesn't make sense! Remember, a datatype is not equal to an array of that type, they are two different things. Therefore a string is not compatible with a string array. However, each individual element of the array is a string, and so each of those are compatible with the string type (because they're the same thing)!
Dim var As String = ComboBox1.SelectedValue
Dim temp() As String = Split(var, ",", -1, CompareMethod.Binary)
Dim name As String = temp(0)
Or maybe "name" isn't an array and the goal is to populate "name" with everything up until the first comma, in which case the fix would be:
Dim name as String = var.Split(",")(0)
Note: assumes that var is not Nothing.
I am using VB.NET code.
I have got the below string.
http://localhost:3282/ISS/Training/SearchTrainerData.aspx
Now I want to split the above string with "/" as well. I want to store the value SearchTrainerData.aspx in a variable.
In my case
Dim str as String
str = "SearchTrainerData.aspx"
What would be the code which will split the above string and further store it in a variable?
Try to use the function String.Split.
Your "string" is obviously a URL which means you should use the System.Uri class.
Dim url As Uri = New Uri("http://localhost:3282/ISS/Training/SearchTrainerData.aspx")
Dim segments As String() = url.Segments
Dim str As String = segments(segments.Length - 1)
This will also allow you to get all kinds of other interesting information about your "string" without resorting to manual (and error-prone) parsing.
The Split function takes characters, which VB.NET represents by appending a 'c' to the end of a one-character string:
Dim sentence = "http://localhost:3282/ISS/Training/SearchTrainerData.aspx"
Dim words = sentence.Split("/"c)
Dim lastWord = words(words.length - 1)
I guess what you are actually looking for is the System.Uri Class. Which makes all string splitting that you are looking for obsolete.
MSDN Documentation for System.Uri
Uri url = new Uri ("http://...");
String[] parts = url.Segments;
Use split(). You call it on the string instance, passing in a char array of the delimiters, and it returns to you an array of strings. Grab the last element to get your "SearchTrainerData.aspx."