The static variable in C language and Cpp language. How to use static variable in your project which is written using C/Cpp/Objective-C language.
"Programmers usually deal with header files and implementation files. Compilers don’t – they deal with translation units (TUs), sometimes referred to as compilation units. The definition of such a translation unit is very simple: Any file, fed to the compiler, after it has been pre-processed. In detail, this means that it is the file resulting from the pre-processor expanding macros, conditionally including source code depending on #ifdef and #ifndef statements and copy-pasting any #includeed files."
- Internal and External Linkage in C++ http://www.goldsborough.me/c/c%2B%2B/linker/2016/03/30/19-34-25-internal_and_external_linkage_in_c%2B%2B/