[removed] What is the difference between `if (!x)` and `if (x == null)`?

Question

What is the difference between if (!x) and if (x == null); that is, when can their results be different?

Answer 1

!x tests for a false value. This will be true for any value that can propagate to false for whatever reason. This will be true for permutations of false, 0, etc etc.

x == null is different because var x = 0 will NOT be null... but WILL be false.