string.IndexOf search for whole word match

Question

I am seeking a way to search a string for an exact match or whole word match. RegEx.Match and RegEx.IsMatch don't seem to get me where I want to be.
Consider the following scenario:

namespace test
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = "SUBTOTAL 34.37 TAX TOTAL 37.43";
            int indx = str.IndexOf("TOTAL");
            string amount = str.Substring(indx + "TOTAL".Length, 10);
            string strAmount = Regex.Replace(amount, "[^.0-9]", "");

            Console.WriteLine(strAmount);
            Console.WriteLine("Press any key to continue...");
            Console.ReadKey();
        }
    }
}

The output of the above code is:

// 34.37
// Press any key to continue...

The problem is, I don't want SUBTOTAL, but IndexOf finds the first occurrence of the word TOTAL which is in SUBTOTAL which then yields the incorrect value of 34.37.

So the question is, is there a way to force IndexOf to find only an exact match or is there another way to force that exact whole word match so that I can find the index of that exact match and then perform some useful function with it. RegEx.IsMatch and RegEx.Match are, as far as I can tell, simply boolean searches. In this case, it isn't enough to just know the exact match exists. I need to know where it exists in the string.

Any advice would be appreciated.

Answer 1

You can use Regex

string str = "SUBTOTAL 34.37 TAX TOTAL 37.43";
var indx = Regex.Match(str, @"\WTOTAL\W").Index; // will be 18