What's the most efficient way to determine whether an untrimmed string is empty in C#?

Question

I have a string that may have whitespace characters around it and I want to check to see whether it is essentially empty.

There are quite a few ways to do this:

Answer 1

Since I just started I can't comment so here it is.

if (String.IsNullOrEmpty(myString.Trim()))

Trim() call will fail if myString is null since you can't call methods in a object that is null (NullReferenceException).

So the correct syntax would be something like this:

if (!String.IsNullOrEmpty(myString))
{
    string trimmedString = myString.Trim();
    //do the rest of you code
}
else
{
    //string is null or empty, don't bother processing it
}