How to use string.Endswith to test for multiple endings?

Question

I need to check in string.Endswith(\"\") from any of the following operators: +,-,*,/

If I have 20 operators I don\'t want to use ||<

Answer 1

Using String.IndexOf(String):

str.Lenght > 0 ? "+-*/".IndexOf(str[str.Lenght - 1]) != -1 : false

Answer 2

If you really want to, you can use De Morgan's laws to replace x || y in your code. One version says:

!(x || y) == !x && !y

If you want to have the same result, we just need to negate the entire expression twice:

x || y == !!(x || y) == !(!x && !y)

Answer 3

How about:-

string input = .....;
string[] matches = { ...... whatever ...... };

foreach (string match in matches)
{
    if (input.EndsWith(match))
        return true;
}

I know it is dreadfully old school to avoid LINQ in this context, but one day you will need to read this code. I am absolutely sure that LINQ has its uses (maybe i'll find them one day) but i am quite sure it is not meant to replace the four lines of code above.