C/C++ static variables

1. Links

http://en.wikipedia.org/wiki/Static_variable

2. Notes

- Static global variables: variables declared as static at the top level of a source file (outside any function definitions) are only visible throughout that file ("file scope", also known as "internal linkage").

- Static local variables: variables declared as static inside a function are statically allocated while having the same scope as automatic local variables. Hence whatever values the function puts into its static local variables during one call will still be present when the function is called again.

- Static member variables: in C++, member variables declared as static inside class definitions are class variables (shared between all class instances, as opposed to instance variables).