It is not possible to have floating symbols. Once a symbol is bound, it remains bound. The watches are remembered between sessions. Whether or not the symbol has been bound is a part of this information. If the program enters a scope where a bound symbol is not visible, the value field changes to Out of scope.
Arrays and Structs
The Watch window can be used for watching C arrays and structs as well
as simple variables. The syntax is the same as in C (use braces ('[' and
']') for arrays and dot ('.') for structs). Dereferencing pointers is supported.
When watching arrays, variables can be used for dynamically indexing the
arrays. It is for example possible to watch "my_array[i]" if i is an integer
in the same scope as the array my_array.