remove last two string char!

Question

The following code:

If checkboxList.Items(i).Selected Then 
   .Fields("DESC1").Value += checkboxList.Items(i).Text + ", "
End If

should produce output such as "A, B, C,(space)", which will then be bound to a dynamically created GridView. I would like to remove the last two-char string, that is ",(space)". How can I do this?

Answer 1

It seems you just want to get "A, B, C" from "A, B, C, ". A bit of simple string manipulation should do the job:

Dim input = "A, B, C, "
Dim result = input.Substring(0, input.LastIndexOf(","))

This is more versatile than simply removing the last two characters, since it looks for the last comma, which is what I believe you are after.

Of course, the fact that you're adding on these two chars in the first place sounds a bit dodgy. I'd need to see more context to show how this can be avoided, however.

Answer 2

I wouldn't add them on in the first place :) try

If checkboxList.Items(i).Selected Then    
    if .Fields("DESC1").Value Is System.DbNull.Value then
        .Fields("DESC1").Value = checkboxList.Items(i).Text
    else
        .Fields("DESC1").Value +=  ", " + checkboxList.Items(i).Text
    End If
End If

Answer 3

You can use .TrimEnd(", ".ToCharArray()) on the string, or you can use SubString:

strLetters.Substring(0, strLetters.Length - 2)

Answer 4

use

.Fields("DESC1").Value += checkboxList.Items(i).Text + ", "

. Fields("DESC1").Value = .Fields("DESC1").Value.TrimRight(new []{',',' '});

PS:- sorry if it is not valid vb syntax :)

Answer 5

There is also just "Remove":

string k = "okay";
string s = k.Remove(k.Length - 2, 2);

Answer 6

Does VB have a ternary if operator?

If checkboxList.Items(i).Selected Then 
    .Fields("DESC1").Value += checkboxList.Items(i).Text + (i == checkboxList.Items.Length-1 ? "" : ", ")
End If

Answer 7

Take a look at String.Join, which may do what you want, without the need to manipulate the final two characters.

Answer 8

This will remove all trailing , and/or [space]:

.Fields("DESC1").Value = .Fields("DESC1").Value.TrimRight(", ".ToCharArrray())

Answer 9

For info, string concatenation is expensive. It looks (from the i and from the results) like you should really be using a StringBuilder; some rough pseudo-code (in C#, but trivial to translate to VB.Net):

StringBuilder sb = new StringBuilder();
for(int i = 0 ; i < checkboxList.Items.Count ; i++) {
    if(checkboxList.Items[i].Selected) {
        if(sb.Length > 0) sb.Append(", "); // add separator
        sb.Append(checkboxList.Items[i].Text); // add text
    }
}
someOjb.Fields("DESC1") = sb.ToString(); // use result

Answer 10

var selectedValues = checkboxList.Items
    .Where(i => i.Selected)
    .Select(i => i.Fields("DESC1").Value);

var result = String.Join(", ", selectedValues);