Firstly I understand that there are several ways to do this and I do have some code which runs, but what I just wanted to find out was if anyone else has a recommended way to do this. Say I have a string which I already know that would have contain a specific character (a ‘,’ in this case). Now I just want to validate that this comma is used only once and not more. I know iterating through each character is an option but why go through all that work because I just want to make sure that this special character is not used more than once, I’m not exactly interested in the count per se. The best I could think was to use the split and here is some sample code that works. Just curious to find out if there is a better way to do this.
In summary,
I have a certain string in which I know has a special character (‘,’ in this case)
I want to validate that this special character has only been used once in this string
const char characterToBeEvaluated = ',';
string myStringToBeTested = "HelloWorldLetus,code";
var countOfIdentifiedCharacter = myStringToBeTested.Split(characterToBeEvaluated).Length - 1;
if (countOfIdentifiedCharacter == 1)
{
Console.WriteLine("Used exactly once as expected");
}
else
{
Console.WriteLine("Used either less than or more than once");
}
>Solution :
You can use string‘s IndexOf methods:
const char characterToBeEvaluated = ',';
string myStringToBeTested = "HelloWorldLetus,code";
string substringToFind = characterToBeEvaluated.ToString();
int firstIdx = myStringToBeTested.IndexOf(substringToFind, StringComparison.Ordinal);
bool foundOnce = firstIdx >= 0;
bool foundTwice = foundOnce && myStringToBeTested.IndexOf(substringToFind, firstIdx + 1, StringComparison.Ordinal) >= 0;