string.IsNullOrEmpty() vs string.NotNullOrEmpty()

Question

I\'m curious if any developers use string.IsNullOrEmpty() more often with a negative than with a positive

e.g.

if (!string.IsNullOrEmpty())

Answer 1

"NotNullOrEmpty" is ambiguous, it could mean "(not null) or empty" or it could mean "not (null or empty)". To make it unambiguous you'd have to use "NotNullAndNotEmpty", which is a mouthfull.

Also, the "IsNullOrEmpty" naming encourages use as a guard clause, which I think is useful. E.g.:

if (String.IsNullOrEmpty(someString))
{
   // error handling
   return;
}
// do stuff

which I think is generally cleaner than:

if (!String.IsNullOrEmpty(someString))
{
   // do stuff
}
else
{
   // error handling
   return;
}