Error in converting string to float

Question

Hi there, I have a rookie's question about the conversion.

string Descript1 = ":1:2:3:4:5";
Regex pattern = new Regex("(:)");

foreach (string sub in pattern.Split(Descript1))
{
    if (sub != ":")
    {
        float a = Convert.ToSingle(sub);
    }
}

But this code keep pumping out the error: "the string was not in the correct format.".

Anyone could help me?

Thanks.

Answer 1

You shouldn't need the regex pattern. The Split method has an overload that accepts your delimiter as a string.

Do a console.writeline (or breakpoint), and make sure you are getting a string that makes sense for the conversion.

Answer 2

if (sub != ":" && sub!="")

Answer 3

I'd imagine your array would begin with an empty string (because of the : at the beginning of your string). Step one is to use a debugger to figure out whether the array contains what you think it contains.

Answer 4

The first result of the split is an empty string, i.e. what's before the first colon in the string.

Skip empty strings instead of skipping ":" (as that never can appear in the result):

string Descript1 = ":1:2:3:4:5";
Regex pattern = new Regex(":");

foreach (string sub in pattern.Split(Descript1)) {
  if (sub.Length > 0) {
    Single a = Convert.ToSingle(sub);
  }
}

Answer 5

Try this:

string description = ":1:2:3:4:5";
var floats = from part in description.Split(new char[] { ':' }, StringSplitOptions.RemoveEmptyEntries)
             select float.Parse(part);
foreach (var f in floats)
{
    Console.WriteLine(f);
}

Answer 6

Thanks guys. I got it.

Answer 7

Regex.Split is returning a empty string at the beginning of your array (returned from Pattern.Split)

Change it to the following and it should work:

string Descript1 = ":1:2:3:4:5";
Regex pattern = new Regex("(:)");

foreach (string sub in pattern.Split(Descript1))
{
    if (sub != ":" && sub != string.Empty)
    {

     float a = float.Parse(sub);
    }
}